Also notice that this is a repeat of Mac OS vs Windows in the early '90s. Then, part of the reason that true Windows GUI programs replaced DOS as fast as they did, and we didn't have a period of "Windows as a way to show multiple DOS Windows" was that people (Microsoft being an important one) had to learn GUI programming to support the Mac.
Apple is making the bet that people want to use apps that are all designed with touch interfaces in mind and that people prefer a simpler computing model. Microsoft is betting that backwards compatibility is more important.