I think you are right. Much of the copyleft ecosystem is built on cross-organizational groups where no one entity wants to foot the whole bill for development but are willing to pool resources together to get the big projects done. The recent popularity of Kickstarter is also another similar situation where the development cost is paid for up front so that small customers can get big projects done.
Even in the absence of copyright allowing one to sell licenses in the traditional sense, if the software is worth having then it seems that there should be someone(s) who will pay for it. I don't know if Redhat is the exception that proves the rule or a demonstration that you can still charge money and do well without using the traditional copy rights. They haven't folded just because CentOS exists for example.