I don't expect to keep using any platform till I die, unless I end up living a sort life, lol. But that said, I won't switch just for the sake of switching.
When it comes to any field, especially when your competitor has such a big head start, you cannot come to market and not offer a significant differentiator -- in features, price, convenience, etc. If people have already invested time, money, know how, etc., into another product, and that product has already established itself as a relatively reliable and convenient one, you're not getting them to switch just because you joined the market. And the more momentum a competitor already has, the harder it is for you to gain a foothold, even among people who are buying for the first time.
In tablets, MS isn't offering enough to differentiate so far -- in price, features or convenience. And just having Bill G say something like a keyboard is a differentiator is a joke, especially when there are plenty of choices for iPad keyboards for those who want them.
I don't disagree with anything you've said....but let's not for get that lots and lots of folks have Windows stuff already...the easy to moving your work to a windows tablet could be compelling for many....the only thing stuff folks...is...well, $1200, and that lousy interface.
If it weren't for the fact that I own a very nice Windows convertible that runs Win7, I'd get a MS tablet (or one of the others) in a minute. It would not replace my iPad, however. But I have a well-defined use for a Windows laptop, which to me, is what a Surface is....in my mind it is just not an iPad killer. No way....but then again, it doesn't need to be to live in my world. I think if of it as the next step when I upgrade my laptop.
I thought that whole keyboard thing was a big joke...but it seemed to make a different to some people...but the notion of paying extra for it...it's like they wanted to force the idea of it being a tablet right down your throat....while the truth is to do anything useful with a Surface, the keyboard is a requirement (IMO).