Stephen, I can take my app and go home, but then I'm alone. Institutions do *not*, by and large, want to be supporting their own custom apps when they can possibly avoid it. Given a choice between that and buying a mediocre closed source app, they'll buy the closed source app.
The whole point is being in a community. If I'm a developer, I can lead a team of developers and hopefully form a new committee. Have you ever heard of a sponsoring organization creating a new Open Source community with money? It doesn't happen. The non-developer stakeholders can't go it alone and they can't start their own community either. They're locked in.
