> Instead of constantly singing the praises of open source

i would differ in my opinion, because it's not the 'singing praises' that's the root cause, but that the creator of said FOSS library expecting money in some form for having provided value up front (either contributions or donations etc).

That's an expectation that will never live up to reality.

> we have to find a sustainable way to reward the developers

this exists already - charging for the software you develop. Or, develop a business model around the software - aka, the software is free, but is just the bait for consulting business.