Now I want to hit another more or less touchy subject, free software doesn't mean free-of-charge software, monetization should be integral to the software center and in my opinion it should have a pay-what-you-want option while leaving the developer the minimum price tag as choice.
I don't think you need to be worried about this opinion at all. This is exactly what I believe, and most people who actually contribute to FOSS agree as well. Those who disagree enough to attack you probably don't contribute or are simply trying to troll for their own amusement.
With that said, UBports is in a place where it can't profit monetarily from things like app sales, due to our (soon to be) nonprofit nature. People who put apps on the store, though? That's likely allowable.
Really, I think we should watch the development of the Elementary App Center, which offers a "pay what you want" model for the participating applications. If that turns out to be successful, I would fully support the idea being used to improve the OpenStore. That's entirely the OpenStore team's decision to make, though. Otherwise, I see Patreon as a great way for people to be supported in a recurring way for the time they pour into their projects.