Here's a link to an article about "modern classical" music, and why people tend not to like it as well as "classic classical" music:

http://www.mypianotalk.com/forums/topic/298/audiences-hate-modern-classical

Personally, I find both classic and contemporary classical music to be a bit boring. It's not because of the repetitive patterns or lack of them. Rather, I find the instrumentation available to an orchestra to be a bit boring, and all the musicians to be sort of superfluous.