After a long hiatus Quicksilver was taken over by a dedicated team of contributors who resumed active development[1]. Open-source worked after all, as this wouldn't be possible otherwise.
What happens the next time something gets broken after a major OS update? I can't wait for a few months to get it working again.
I'm not saying that open source software is lousy. I use it all the time. It's just that in certain situations you need the person there who created it.