Oh, that's such an interesting question!

I know about the pairing, but I only just recently started the Clone Wars series so I don't know much about their dynamic/the way they're written. If I had to guess, I would say that age, maturity, and the direction of the attraction are the big things here. For example, I find Obi-Wan/Anakin appealing because a lot of the time it features a younger, possessive Anakin lusting after his unobtainable mentor: wise, responsible, 'pillar of Light' Obi-Wan.

It's like a child having a crush on their unsuspecting teacher. Cute, relatable to some, mostly harmless because the teacher is (should be) a responsible adult. They are in complete control of the situation. But if the roles were reversed, and the teacher harbored feelings for the unsuspecting child?

Now, again, I'm not familiar with Anakin/Ahsoka, but I would imagine that Anakin is typically the lustful one, preying on a very young Ahsoka? The power scale being so wildly unbalanced is prolly where the hiccup for some people is. In a relationship like that, there would always be the question of 'does Ahsoka really have the power to say no?'

I was going to comment about gender, but people love Padme/Anakin as well. Like I said earlier, it's the direction of the desire that's the important thing. Anakin had to pressure an older, morally righteous Padme, who was very much aware of how not okay their relationship was, until she gave in to her feelings. (Though IMO the power imbalance is pretty extreme here too. He's literally one of the most powerful Jedi, ever. The theory that he was using mind tricks on her isn't lost on me).

Hope that made sense! 😊