Fair enough, but we floated the idea of support contracts (with a large company, not a tip or grant to a couple of developers) and still didn't get much interest. As far as I can tell companies are not offering contracts or asking for guarantees either.

There are clearly exceptions. Red Hat is obviously one, as are many successful OSS companies. But a lot of those companies play hardball with dual-licensing - so if you want it for free, you better love GPLv3! :-)