Why do people hate Wulbren so much?

possible spoilers!!!

I see people dog on him a lot in this sub and i’m mildly confused why. At most i found him mildly annoying but nothing crazy.

I will say part three is the part i’ve explored the least in all honesty( have an addiction to starting new games every time i hit the city) so i don’t know if im missing some info or not. or some info from part 2. honestly the whole underforge area was quite confusing and i did not explore it to its full potential yet. So if i just missed a huge plot point let me know. or just why you hate him.