Aside from the many valid MS-specific issues, my recent take on "why I abandoned X for Y" is that programming is still an inherently hard and frustrating activity. The final results are frustrating compared to the promise of X; The problems of Ruby-on-Rails or .NET or beautiful Perl one-liners whatever don't appear tell you get to a certain scale. So the next great thing (or the retro-great-thing or whatever) can always look good compared to the big mess you've land yourself in. And .NET could well be the best engineered system in the world for all I know but it's crazy frustrating once you get to a certain scale.

Therefore, we should abandon X and do Y, whose promises haven't yet been broken.