XB1 isn't even released. Under what metric is it a failure? People can bitch about this policy or that feature, but until sales numbers roll out, I'm not calling it one way or another.
Whether or not a particular version of Windows sucks, people and businesses are still buying windows computers, and MS products, and MS services, and support, etc...
RT did suck and was a failure, and that's because the people who would have purchased one already knew it had shitty hardware. Personally, I've simply been waiting for the Haswell Surface Pro.