Hmm. I guess I was envisioning the service as being the non-profit, and the disbursement need not be to other non-profits.

But this brings up a few interesting points. First, if you give only to the founder, and not the contributor, will this engender resentment? Second, ideally the result would be that the founder would work more on the project in a consistent way, but that sort of gift would need to be something more along the lines of a stipend over the course of a year or two. Third, if the amounts were large enough (which would be the case if every 6-figure dev gave $1k/year), you could do something along the lines of the MacArthur foundation so-called "genius grants".

Foundation, not founder; foundations are required to be much more accountable with funds than individuals are. I'm suggesting in most circumstances that it's preferable to give to an accountable organization chartered with the stewardship of a project, rather than to any particular individual.

Well this is a useful discussion, because I'm realizing how much I want to give the maker/user community itself the power to hold itself accountable. To take your point to the logical conclusion is to assert that all successful OSS projects should have a foundation, or even a for-profit org. I'd like to see something looser, a dynamic, democratic assignment of value by those who benefit the most.