I don't really dislike any genres. I can happily listen to most genres. Check out my last.fm, if you don't believe me.
I really dislike when the importance of something is vastly overstated by the majority of music fans/critics though. A good example of this is anything released by Smithsonian Folkways. No, those ethnic "tunes" are not important in any way. Royal Indonesian court music did not influence modern pop music. Shut up. They are interesting as an obscurity/piece of folk history, but they are not nearly as important as some of them are made out to be. I think this is due to multiculturalist impulses to falsely credit women/minorities with "grand" achievements that they aren't really worth of, or perhaps just nerds looking to put their obscurantist musical interests on some pedestal so they can feel important as musical ethnologists or some bullshit.
FUCK YOU
di giove l'ira, e in un baleno va all'eghe in seno, da regal sede
tosto provvede, fa i generosi destrier squammosi ratto accoppiar