It's all very easy to announce the composers you do like and who your favourites are. You don't have to justify your taste. No-one is going to challenge you. However, if you were to say: "I particularly dislike ______". It's inevitable that somebody will ask you: "Why not?" ....especially if the composer is of some renown. My former A'level composition tutor, Arthur Butterworth always had a good word for any composer that I'd mention, except......... Mahler! He conceded that the man was supremely gifted and one of the best orchestrators of his generation, but his music would leave him cold. He couldn't stand it. My university composition tutor at university, Piers Helliwell, felt the same way about Phillip Glass (although justifying that particular dislike is a lot easier than justifying a dislike for Mahler) and Italian Baroque music such as Vivaldi and Scarlatti (as did Stravinsky).
So, are there any famous composers out there that freeze you up, and you just can't put your finger on it? Especially composers whose contemporaries, you DO like. I'll start you off with my least favourite composer (that everybody else seems to like)................. Rachmaninov. Can't stand him.