I believe I read in another thread that TrueCrypt did not get many donations. I'd be a bit depressed if I worked long and hard on a project that people seemed to appreciate, but not enough to crack open their wallets and toss a few bucks my way, and then some third party comes along and quickly raises $70k to audit my code.
Given the anonymity of the developer(s), how would anyone know this?
However, the downside of being anonymous is that it makes it hard to ask for donations (in places other than your website).
If, and it's a big if, the reason for them throwing in the towel like this, was compensation, I think it would have been handled a lot of other ways.
My money is on an NSL and this was their way of telling us about it.