It's a good question. I guess I would say that in my limited experience, co-operatives that fund by providing products and services (food, housing) seem to accu

It's a good question. I guess I would say that in my limited experience, co-operatives that fund by providing products and services (food, housing) seem to accumulate less organizational bloat and overhead, because their continued funding is directly coupled to providing a good user experience. But in foundations and donation-based nonprofits, what you see is that they become organizationally focused on chasing donations, they have more and more irritating "please donate to us" fundraising staff, they may have to bend their mission towards whatever can please the local philanthropists, and they sometimes end up seeming more worried about organizational survival (via procuring money) than with whatever their mission is supposed to be. Another way of putting this is that it seems pretty hard to make voluntary donations provide stability, and organizations like stability. I'm open to having my mind changed about this, but it seems to me that it creates some major new organizational failure modes when you decouple the mission from the source of revenue.