[gjm11]

What else were they supposed to do? Let it compete against Windows 3.1 instead? Just not release it for another three years?

Well, maybe the second of those would have been a good idea: spend a few more years adding features and polish. But presumably they wanted basically that OS out there competing with iOS and Android. And perhaps they reckon more people will buy Surface and Windows Phone devices when the UI feels more familiar on account of using it on desktop and laptop computers.

And, actually, it's hard to see how Windows 8 would get more users, or make more money for Microsoft, if they wait three years instead of starting to sell it now and gradually improving it over those three years. I can see only one way: if the wait lets them make more radical changes that they can't apply to an OS that's already out there being used. But there's a limit to how much you can change at once without alienating everyone, and Windows 8 may be pushing it already.