I don't hate Six Flags at all. I generally always have a great time at their parks, however they are one of the worse run major chains. For example, I really enjoy Magic Mountain, however when I'm there I can really only focus on the coasters. They lack in a lot of other things.
I don't hate them though. I just don't expect much out of them.
But lets look at a park like Europa Park, easily one of the best parks in the world and my personal #1. The only thing they lack is a "stand out" flat ride. However, they have the best of everyting else so it makes up for it.
Six Flags is like a student that gets an "A" in one class (Roller Coasters), but fails everything else.
While parks like Europa, pretty much every Disney park except DLP, Busch Gardens, and Universal gets from B+'s to A+'s in everything.
-- James