The last character you really hated

[Reece]

If you don't hate a villain for the things they've done, they are NOT a good villain.

Interesting point, though a debatable one.
How do you account for different people hating different things? For example, I loved Nealapph, I thought he was a fantastic character... I was actually really surprised to see Aaron say he hated him (though it does explain the change to Tearen).
But based on what you said, that should mean that in my opinion, Nealapph was a bad villain, which isn't true at all.