I happen to disagree with Joel on that one - in particular circumstances :) also the aim might be to encourage those who tend not to do "something for nothing" to contribute :)
(The common goal thing is quite good....)
(The common goal thing is quite good....)
It's possible that there is incentive to be had in the 'common goal'; "The Foo Project's Charity is the FSF; If we squash all the bugs by Labor Day, 80% of donations will go to the FSF. Otherwise, 50%"