People don’t like paying for music and they don’t like paying for software. It is not easy nor common for an individual or a small project to gather any significant money for free software development, i.e. to get real compensation for some work and to make living of it.
But fundraising for this SBCL work on threading improvements by Nikodemus Siivola was completely successful and the first fruits of that project are already available. SBCL is a free Common Lisp compiler and Nikodemus Siivola is one of its respectable developers. Common Lisp community is somewhat special, SBCL is popular and some people use it for their private business. Maybe these facts explain the success of the campaign, who knows. Interesting.