I think Google could make a big difference by licensing an email antispam API like Automattic does with Akistmet. You'd get the best of both worlds.
Also, 80beans is using it and they only have a team of 6.
It's no surprise that they concentrate on marketing their business software to businesses though. That's who's going to pay for it. A CS department is going to use whatever the school uses and a non-profit is better served by Google Apps (which is discounted heavily for non-profits).