Your dislike for him is your inability to appreciate the best composer the world has ever produced.
Dislike and appreciation aren't the same thing. I said that I disliked him, but I never said that I didn't appreciate him, so don't tell me who I appreciate and who I don't appreciate.
And to say that he's the best composer the world has ever produced is entirely subjective.
Most influential composer? Probably
Best composer? No
Bach is in a realm beyond any composer you can name.
EVERY composer is in a realm beyond any other composer you can name! Wanna know why?
Because they all made different music!
Music isn't a contest because there aren't any parameters that we can use to discern who's the better composer.
Incidentally, another way of expressing this sentiment is by saying that all music is the same; it's just a bunch of sound waves at different lengths and frequencies hitting your ear and your nerve fibers converting those sound waves into electrical impulses which are then sent to your brain through the auditory nerve system so you can interpret.
So the way you view Rachmaninoff can sound like the way I view Bach and the way I view Bach can sound like Rachmaninoff to you.