Good for him, no donations should translate in to obligations, they're donations, voluntary and are considered to be a reward for services rendered in the past, not the future.
Typically when someone is as driven as this and you get the output of all the labour that went in to it the proper words are 'thank you' and if you feel like rewarding the creator then that's great. But that does not entitle anybody to future preferential treatment or even any guaranteed output level.
I wonder whether most donors actually understand this, with non-donors being the primary complainers.
Randy Milholland, the webcomic artist behind Something Positive, quit his job and funded himself for a year with donations to spend more time on his comics. When his output was still less-than-daily, he got a flood of complaints. "We gave you money and you're still not updating as often as you promised!" When he offered to refund the donations of anyone unsatisfied, not a single donor took him up on it. Apparently most (or all) of the complainers hadn't donated, but still felt entitled to greater output.
This is not to say that Rich is making a mistake by no longer accepting donations. Even if most complaints are from non-donors, their (unfounded) sense of entitlement comes from the fact that donations are happening. Still, I hate to think that people happy to donate can no longer do so because of the negative effects caused by non-contributing complainers.
interesting point - I think people who "donate" do it out of gratitude rather than creation of entitlement. By virtue of that, the complainers are less likely to come from the actual donor list.
My empirical evidence comes from the Cyanogenmod Android project - where "when can I haz gingerbread" or "this sucks - why arent you spending enough time fixing <bug>" is always from non donors.
NOTE: it is easy to see this trend on the CM forums, because your forum handle displays whether you are a donor or not. That I think is an easy way to lower the credibility of flamers (something that isnt possible on Clojure Google Groups). But then again, maybe that in itself give rises to the expectation that "if I donate, I can flame". I havent seen it happen on the CM forums though.
Act 2312863 of "how to fund open source software". It's not easy. Indeed, it's pretty much impossible to extract a proportional amount of the value that users derive from your code.
Personally, I'd have no problem blowing people off who ask for more than they were promised if it got to this point. Then again, that might bring negativity to the community, so I can see how the decision to just stop personal donations makes sense.
Typically when someone is as driven as this and you get the output of all the labour that went in to it the proper words are 'thank you' and if you feel like rewarding the creator then that's great. But that does not entitle anybody to future preferential treatment or even any guaranteed output level.