He's a villain, to hate him is to not enjoy the writing, in fact it's pretty much the exact opposite, we hate him because he's a villain, as he is written to be one.

You said it yourself.

Why does he have to be good or righteous to be a fan favourite?

Not being someones subjective favourite character != hating good writing.

You're so dismissive of those who don't agree with your own opinion it just makes me want to call you an asshole who pretends to be some intellectual and morally superior being but proves themselves wrong at both counts in one very short paragraph which somehow deconstructs its own argument immediately after making it.