Sunken cost fallacy... fallacy
You only know something is not a profitable venture looking backwards, but not forwards. Think if Google would have given up on search as a sunken cost before it started to roll (Yahoo is established, you're wasting your time with a similar product)... Point being that you can always declare something dead and that you are just throwing good money after bad, but there is always the possibility that you can turn it around and obtain an ROI. It is only a lost cause if you decide it is a lost cause. Not simple at all.
On Windows mobile, I think MS has a solid path forward here. Surface and the universal app, continuum strategy sounds sensible to me. I think it could work. Apple is struggling and people like, but are not thrilled, with Android. It is far from over.... I think Microsoft also remembers what happened to IBM when they decided to just quit OS/2 and hand over the market to Microsoft. IBM did alright with side lines (similar to your Echo idea) but never regained their importance in the tech world after quitting the primary end user platform. It is smart of MS not to throw in the towel.... The mobile game is far from decided.
Biting the hand that feeds IT
