Just my own opinion but I don't think people writing likeable villians are a problem.I think it's that fandom has a tendency to kind worship villians and find any way to justify their actions no matter what they are (murdered, genocide, rape) but we as writers don't really have control of fans/fandoms reactions after the writing has left our hands and entered the public space. Write a likeable villians ,write one we can sympathize with. That way we can see how easy a path that is to follow.

Yes, I agree, and I answered an ask along these lines not long ago. It’s a difficult decision for any creator what kind of content they put out and how they should portray it. Consumers of media always have varied, sometimes very negative, reactions to anything that’s put out regardless of the intent behind it or the realism of its circumstances.

Creators should, for their sake and their audiences’, be conscious of how they portray even tame subjects, but ultimately they have no control over the perceptions of others. That’s why “write for yourself first” is so important to remember, just to stay focused.