30,000+ apps in the market, created by somewhere north of 9,500 devs. Throw in say 1,000 devs associated with android itself. Right there we are talking about over 10,000 devs.
I'd lay odds that less than 5% even knew about any of this.
Umm.. What do those dev's have anything to do with the ROM scene? They code apps in java and release them for money. Maybe you should really research into what's involved with working on the android source. Start here : Documentation (Android Open Source Project)