What they did was confuse the hell out of people. At first Microsoft was touting a tablet that could run Windows Apps called the surface. What they meant was the Surface pro. Instead the device that got released first was the RT and it still had the name "windows". Most people looking at them, and I know of one business that bought a couple, did so thinking they could run existing windows programs. They got 'em home and learned they couldn't.
At least Apple makes it clear that while underneath the hood, both MacOS and iOS share many of the same parts, they are entirely different OS's designed for different purposes. Microsoft failed to do that with the Surface.
The next problem is that the Surface Pro is $1000. At that price what is the incentive to buy it? You can buy a convertible ultra book for just a few dollars more.