Aside from producing what I consider to be mediocre and recycled games time and time again, the biggest thing that bothers me about him is that he's placed himself as THE top dog of Castlevania. HE decides what the official timeline is, HE decides what goes into and gets taken out of the Dracula's Curse cartoon script, etc. Aside from the upcoming arcade game(s), he's been the producer of every Castlevania game for the past few years, and he slags on games that are great, like the N64 games--but the funny thing is, his PS2 games don't even compare, and he shits on Legends but it's actually a fairly decent game. He's even mocked Circle of the Moon in the past, which is no worse than any of his games.
But what I'm getting at is that he is now considered the man behind Castlevania, when all other games before it were pretty much designed and created and directed and produced by an assortment of different people. I'm pretty certain a great deal of the staff members of the first Castlevania game aren't the same as on Castlevania IV or Rondo of Blood. There were always different teams creating different games. IGA has made Castlevania "IGA exclusive," and quite frankly it sucks. Even if he actually made games I enjoy, I'd still probably be pretty miffed that he has such a firm iron grip on the franchise without allowing anyone else to do their own thing.