Do people really care about licenses? Large companies will bury you in costs before you get paid, right? I think by that time it's too late.
The obligation to reach towards the wallet should be earlier. As somebody mentioned somewhere, I think bounties would make sense. The dev can work in anything they like, but can be incentivised to work on something specific if a bounty is on it.
For that however, we would need a third party system where people can pay into a pot for a specific goal, define the key items that have to be fulfilled, and only when they are fulfilled + validated by a third party, is the money paid out.
Or something like that. What other ideas do you smart folk have?