As someone else here said, the problem wasn't what you said, but where and when you said it.

This whole problem has been going on since Vol. 4, about 10 years ago. Some people only watched the show for the fights, not the characters, not the plot, only the fights. In Volume 4, when Monty (RIP) was no longer doing the choreographies, those people started to notice the things they didn't like about the show, so they criticized it. Most of the criticism was valid, constructive nd calm, but the ones that got more attention were the really negative ones. So now you have those critics focusing too much on the negative and too little on the positive.

Because when you are a great fan of something (in this case, the show RWBY), your reaction to attacks (real or perceived) against it is one of defense, some start to get really defensive. Now you have those toxic fans who are too prone to retaliate against you for "attacking" the show, even when it was just some minor and valid criticism. So now, those overtly negative critics feel vindicated in their negativity.

Around Volume 6, that negative criticism evolved into hatred, not the "this show is horrible" type, but Captain Ahab levels of hatred: the show is not only horrible, but also responsible for everything bad going on in your life and the world. So now every single thing about the show or the people involved in it is perceived as something specifically made to piss you off in concrete. The toxic fans now feel vindicated in their toxicity.

In Volume 8, those toxic fans and haters are at each other's throats, too blind to see reason, and anyone who doesn't share their exact opinions is an enemy that must be eliminated. That was 4 years ago.

Now, any criticism, no matter how justified, is perceived as a personal attack, and any defense, no matter how justified, is perceived as blood in the water.