This is in Microsoft's DNA. The more you're re-writing your apps "because everyone will have feature X of platform Y" the more you're not writing web apps that will ultimately make their platform irrelevant.

By iterating on non-compatible releases, you're forced to run on the upgrade/rewrite hamster wheel to take advantage of that feature the last version didn't quite have but should've.

Joel Spolsky coined it "fire and motion" http://www.joelonsoftware.com/articles/fog0000000339.html

"Think of the history of data access strategies to come out of Microsoft. ODBC, RDO, DAO, ADO, OLEDB, now ADO.NET - All New! Are these technological imperatives? The result of an incompetent design group that needs to reinvent data access every goddamn year? (That's probably it, actually.) But the end result is just cover fire. The competition has no choice but to spend all their time porting and keeping up, time that they can't spend writing new features"