Well I“m just starting and this may sound stupid and obvious but I believe if the author feels hatred or just doesn“t like certain character the readers would also probably hate “em too! : D
and omg this is so complicated to say but talking about villains they do count with their motives or reasons of why they do the things they do and well if it is right on their own judgement they do it, and I believe they shouldn“t work to just be against the protagonist all the time and be bad just because they should have more goals beyond being against the protagonist?
I“m not a professional writter but it“s good if characters have other functions more than just their goal in the plot even the extra ones! (something I gotta work tbh xd)
Even sometimes the hero can be also the villain which I think is kinda interesting (because you know what they say your worst enemy is yourself!)
and there“s even stories that do not count with a villain who could be threat to humanity 
just a place where all go by their own and do either good or bad things (neutral like us i think)
and well this far of a hateable or dislikeable character I only have an abusive parent in the story who also impacts one of the mcs
(which sadly is a very common case in life but writting something like this isn“t easy either since I must show the perspective of the victim which is the child who has to deal with him)
That“s all I have for now but might have more hateable characters
aaand I“m done