"We can afford it" is a terrible response to bad PR. He needs to act quickly and make this right. Apologize. Give the guy a free account or something. Everything is (mostly) better.
I'm convinced that half of a PR person's work is convincing others to get over themselves.
The thing is : you usersy might be wrong,or might be right ; but the point is more that users are your even more than your whole business, giving them a good experience is your ultimate goal ; not just selling them a microblogging app.
In my opinion, comparison to steve jobs / apple here are extremely irrelevant ; yes, steve jobs might have earned the right to be obnoxious to bad clients, but the point is that apple as a company doesn't.
For one thing, its because their marketing goes hand in hand with their excellent customer service that this company is successful. Not because one compensate for the other. Its really a shame that somebody can treat its user base like that.
Actually, shareholders would probably be ecstatic.
If Tumblr makes USV huge returns, they can raise a new fund (not like they would struggle right now..) but most funds require "new investments" so why would Spolsky profit other than being a nice guy?
They'll only move on once the service is no longer seen as cool, and the early adopters have - at a modest estimate - absolutely nothing at all to do with this.
People often confuse being curt like this with being effective. Often it's just some guy who had a bad day, is an insufferable asshole or some combo of the above. Customer service and 1 on 1 s with users should never be handled by people like that, though.