[Veen]

I think what he has in mind is not "open source" per se, but the way open source projects tend to organize development—distributed development, unpaid volunteers, open communities, etc. He wants the Cathedral, not the Bazaar—and that's fine; there's no reason everything should be developed by a community of volunteers. But, as you say, there's nothing to stop them centralizing development but releasing source code.

(Plus, I think putting Stephen Wolfram at the top of a Linux kernel-type project is unlikely to work well at all.)