Failure is relative and an opinion. As a product manager I find myself in a constant struggle when it comes to developing a new or innovative solution or idea. We ask ourselves, "is the market ready this", "is the user ready this"... Many times we don't have that answer until we try it out with a customer, but even trying it out means we have to develop and build it. I could potentially see MS product team was in the same scenario. Is the market ready, are customers ready to use this, you don't know what you don't know. I also fully believe MS has a strategy in place to merge the power of a pc, with the convenience of a phone. This could have been part of that strategy. Failure to those not in the know, or for those that scratch their head in disbelief, but maybe not a failure to the product team developing the strategy or to those who can see past it's 1st gen flaws.
My dock is in my home office and i use it with 950 usually to do quick bites of work, research, or email. I would much rather dock my phone than to pull out my laptop in many of these situations. It's not my daily driver, but i use it daily. I can also say that almost everyone that sees me use it are blown away by it.
For me its a total success.