The Cliff Notes probably aren't the whole story: the "Microsoft is Dead" and "Cliff Notes" essays were released in the midst of the selection process for Y Combinator's 2007 summer funding program. Interesting timing...
Actually, it's true that it wasn't a coincidence. I've been doing nothing but reading applications all day, and I missed real work. I wanted to write something, but I couldn't take the time to write a proper essay, which takes weeks. So I just wrote down something I'd been thinking about lately.
(If you were suggesting I wrote it to attract attention to YC, the time to have done that would have been before the application deadline. This is the least useful time to attract attention.)
The first alternative is what I thought: that you were probably taking time away to write. The piece somehow reminded of a time when I was in the middle of doing my taxes and took 45 minutes off to solve a puzzle: dissect an 8x8x27 cubic inch parallelpiped into four pieces that can be reassembled into a cube.
It kind of saddens me that this clarification was necessary, but at least I got a good laugh out of it :)