Oh and they didn't donate.. They get access now and in some cases also a presale.. This more than anything proves user demand which is so important to flush out early.. It's funny you wrote that they donated.. One of the sparkfun commenters said he would not fund a for profit project.. I hope he has a farm because he wouldn't be able to buy much ;)
Of course.. I applied so it's clear there is a perceived value.. But putting a little rubber to the road (which is a good exercise for any entrepreneur) and each piece of the YC package can be had a la carte.. We have advice, early users, legal counsel, and some "User Money" (worth 5x investor money in most cases)
As far as the hundreds of annoying investors, I never really thought of it.. But I guess that happens anyway whenever you take any customer's money.. Except in the Diaspora case, they took the money in advance of development with an expectation that what they were building would satisfy each user which is an impossible scenario from the outset.. Plus the project was open source which I don't think is exactly the norm for a YC investment..
But I think in the end, Diaspora is a fluke.. Statistically and Culturally.. Statistically, it's outcome was not representative of a typical Kickstarter Funding process.. Culturally it was the result of some backlash against Facebook.. That means some of the backers were already pissed off and the open source focus means the some were likely quite vocal to begin with.. I think the combination of these factors and the fact that the funders came in before anything was built leads to the scenario you mention..
Our product was already quite built out before we came to kickstarter and users were pledging for Alpha access and other near future products.. Interestingly enough, we got a front page post on Sparkfun.com today and there were a few non-backers who had something to say about how we should build our project.. The fact that it IS already a project means that they can criticize without making the mistake of backing us and feeling swindled that we don't share their vision.. A few times, the complaint was that we should turn our web based product open source even when they criticized our design.. I think complainers will complain no matter what, and the question of ownership and control is very important as in the case of your investor..