Famous journalist and broadcaster John C. Dvorak (Wikipedia) wrote an article on PC Magazine about Vista’s 11 pillars of Failure.
To summarize, mixing his own words:
1) Too many license types.
2) Code is too big (and therefore buggy).
3) The long-awaited WinFS filesystem is missing.
4) Battery consumption is too high.
5) No real advantage using modern Hard Disks with Vista.
6) “Vista-capable” stickers are bogus.
7) Many device drivers are missing or not properly working
8) Dark advice on upgrading
9) People love XP, in a way or another.
10) Mediocre rollout.
11) Poor performances.
I almost agree with everything, but John is missing another important reason:
12) Ubuntu is so damn good!
Check out Linux Ubuntu 8.04, codename Hardy Heron, for details.
[inspiration: Jeff Barr]