Ya, I thought of that but that doesn't really make sense to me either. Open source projects tend to be free to use. Under this plan you need a token. Which costs money. That's a big change!
Kinda sounds like they're saying that if you change your open source project to a proprietary software project you can get people to pay for it. Now that may be true (for some projects at least) but that's fundamentally changing the nature of what it is you're building.
I don't think app coins/tokens are intended for traditional software that runs in isolation. The proponents of this stuff are talking about P2P networks where other computers provide service to you (e.g. storing your data), so the software may be open source but the service provided by the network is not free.
Of course, some hustlers may try to use app coins in a cynical, Adobe-like business model where you have to pay rent to run software on your own computer and they may be justifiably rebuked.
Something like Golem might fall into this category. It's a project that allows you to use tokens to trade computation time on other people's machines. The software is open source and you could probably set up your own network that uses your own tokens, but likely most users will buy and sell computation at the network the founders set up.
The team got $8.6 million in the initial token sale though. I'm pretty sure they also retained a fair number of tokens. Since there is s fixed amount of tokens the value per token should go up if Golem gets many people to use it and thus the value of the retained tokens rewards the team for their success. A scheme like that of course only would work for a very small portion of open source projects. I could see this work though for pretty much anything that needs hosting. In order to join the network you pay tokens to someone else who is providing that hosting. You could clone pretty much any social network that way. Want to have an account or make changes to your account you gotta pay for the computation.