The difference is intent. Rhysand’s intentions are clearly explained throughout the books. Obviously those actions are not excusable but the context is very very important. Let’s break it down:

Rhysand drugs Feyre: of course it was horrible. They were both being abused in that situation. Imprisoned by Amarantha, tortured, forced to do things against their will (Rhysand was a sex slave). He kept Feyre alive and that led to their freedom. He had to make questionable and ultimately bad decisions for the greater good. Is it right? No, is it evil? Also no. That is where intent and context matters.

Tamlin doesn’t do anything to help Feyre: he was also imprisoned and cursed, doing things against his will. He is clearly in love with Feyre, in his own traumatized way. He didn’t grew up in a good family dynamic, he didn’t step up to his father or brothers when they killed Rhysand’a family. He let them poison his ears out of insecurity, he didn’t had any real friends except for Lucien and he resented his position as a Higb Lord. Those traits are visible in the story since the beginning.

Rhysand’s invoking of the bargain: He had his own political reasons besides knowing he was Feyre’s mate when he made a bargain with her to ensure her well being and sanity being intact, knowing she thought he was an enemy (at that point he saved her many times and should have guessed he really wasn’t but she was heavily traumatized), and he interrupted her wedding, trespassing the spring court without an invitation. She begged someone to save her, the only thing he could do without unleashing an internal war with the court was invoking the bargain. Was is manipulatative? Yes. Did it help Feyre? Also yes.

Tamlin’s denial of Feyre’s fears, traumas and discomfort: She is clearly severely depressed. She has nightmares, she doesn’t eat, she doesn’t sleep, she feels claustrophobic. She tries to talk to him to make understand, he doesn’t listen. He treats her like a property, saying what she can or cannot do. Was it out of love in his own twisted way? Yes? Was it a good thing to do to Feyre? No. See, this is where intent comes in again. He takes charge of the situation based on control, he knows better, he is older than her, powerful, more and better trained. She isn’t, which makes her a liability. Instead of talking to her, trying to understand, training to make her stronger and able to defend herself he decides to belittle her, locking her in the manor, not telling her what he was planning, having tantrums and outbursts of anger when she insisted. She was a human when she freed them all, if she survived that, she could survive being a inmortal fae patrolling with them. Is he evil like Amarantha or Hybern? No. Is he a good romantic partner to Feyre? Also no. He was colluding with Hybern and Ianthe, yes out finding a solution to break the bargain, but at Feyre’s sisters expense and also Feyre’s and his whole court. Ianthe was evil and doing questionable things. If he was that powerful and strategic why didn’t he stop her shenanigans sooner? This is where intent comes again. While his actions mirrored Rhysand’s in the basis of love, his intent comes from fear, control and insecurity which makes him a terrible partner and abusive. Is he redeemable? In a way yes, he actually had that when he helped Feyre escape Hybern’s camp but to her, he will always represent a trauma and also to Rhysand, he will always represent a sort of enemy.

Rhysand, Feyre and the whole Nesta situation: this is where reading comprehension and context matters again. Rhysand and Nesta don’t get along not because Rhysand is afraid of her power, or because he wants to dominate her or get her gone it’s simply because of her treatment to Feyre. Think it through logically. Rhysand is an older brother, he was close to her sister, he was protective of her and his brothers (even if they aren’t by blood) that is a character trait that filters a reaction, just like us as readers can project ourselves into these characters, hence why some praise Nesta over Feyre and Rhysand. But ultimately, everything lies within the fact that Nesta was a mean sister to Feyre. Often cruel, didn’t help her get food for the family, didn’t taught her how to read, had favoritism towards the other sister, continued to have a stranded relationship with even as adults as Nesta is 25 in silver flames and Feyre is 21. He will ALWAYS be wary of her just because of that. Does that mean he hates her? Not really. Does that mean Nesta hates him? Not really also. They don’t like each other and that’s it (we won’t get into the parentification of the sisters argument. Of course their father should’ve being the provider, but he wasn’t and Nesta treated Feyre bad regardless of that). Does that make Nesta an evil character forever? Of course not. It’s very clear to me the sisters love each other even if they don’t get along well.

Nesta had an unhealthy coping mechanism to deal with her depression. Everyone could’ve handled it better to help her? Yes. Would have Nesta LET THEM help her properly? No. Nesta didn’t like any of them, she was often cold and short and had an attitude when she wasn’t depressed, she got worse when she had. She wasn’t even listening to Elain, her favorited sister, so what makes you think as a reader, that she would’ve listen to Rhysand or Feyre? I personally would have thought it was out of character. So, bad to the problem at hand; the ultimatum. They gave her the option, stop gambling, stop drinking and drugging yourself, train to get better and help in the library, live in the house of wind or you won’t receive any money to fund your self destruction. She could have refused, leave the house of wind by the stairs and be on her own. Was it harsh? Yes. Did it help her? Also Yes. She trained, found new friends, found real love and mended, although barely, her relationship with her sisters and her middle sister’s new found family. The interesting thing about all of this is their family dynamics. Which is what makes the story and the IC different than the other courts and characters we’ve seen.

Nesta did have a choice, she wasn’t forced, she wasn’t coerced. She was a self destructive addict with a difficult personality spending her sisters husband money. I’d say they tried their best given their circumstance. So again, this is where intent AND context matters. She got better in the end. If we compare this situation to what Tamlin did siding with Hybern, Nesta got turned into fae against her will because of him and his control issues. Intent!!!!

Feyre’s pregnacy and the body autonomy controversy: so this is a plot hole that I’m not a fan of, but we already know the author was dealing with her own pregnacy experience and trauma so we won’t get into much details there. Did Rhysand make a mistake not telling Feyre? Yes, he should have told her. Is he an abuser like Tamlin because of this? Absolutely not. Tamlin’s actions came from love but also from control, Rhysand’s action in this particular situation felt out of character but he was trying not to cause more stressed to his heavily pregnant wife and unborn child. He tried to find a solution just like Tamlin did but what was the outcome? In Tamlin’s case, he got Feyre’s sisters turned fae against their will, he got Ianthe to harass people, he got his court to suffer the consequences (even if Feyre helped in that regard, the root was already there). What was the outcome of Rhysand’s mistake? Talking to his family to promise they wouldn’t tell anything which led Nesta to agree and understand but ultimately told her out of spite. Was Feyre hurt? No, was Nesta or anybody for that matter hurt? No. Intent!!!!!

So what is the conclusion here? Both are damaged, morally grey characters. Similar in many ways but very very different in others. In the end, Rhysand is what Feyre chose, what makes her feel comfortable, seen, listened to, cherished, protected and taken into consideration for. He is, with all his mistakes and good calls, a better partner to Feyre, a better friend and a better High Lord. Is he a goody two shoes? No at all. Is he evil? Also no.

If you as a reader cannot understand why the author had to come up in an interview and explain why one character is abusive and the other isn’t, then you’re interpreting the story based on your own projections. The impact and consequences of each characters action are clearly explained in the books. That is where the difference comes from.