And? Every other person benefits the same with the code contributed under the licenses in play. I fail to see the issue. With llvm for example they seem to be upstreaming a lot of their xcode backend stuff as they get time. So that statement of many copyleft proponents that only copyleft encourages upstreaming rings hollow to me.

Hell go talk to people from Redhat about custom gcc forks that target chips that aren't upstreamed to gcc. Just because you're using gcc and modifying it doesn't mean you'll actually be contributing the code if its all internal.