Difference between good jazz and bad jazz?

I've started listening to some jazz artists, and after moving past obvious greats (Miles Davis, John Coltrane, Wes Montgomery, etc) I want to branch out, but I've come across a problem: I know that there is such a thing as good jazz, and I know that there is such a thing as bad jazz, but what's the difference? I'm not trying to become pretentious about what I listen to, I'm really just wondering what the difference is. Please, no answers about how there is no difference, that it's all bad. I have a fairly good understanding of music theory, so feel free to explain using musical terminology. Any light that somebody could shed on this issue for me would be greatly appreciated. Thanks!