I think MS's big problem (in terms of their consumer offerings) is they always have unrealistic ideas of what they're going to achieve, and once they realise they're not going to achieve market domination in every sector then they just give up on things, be it hardware, software, services or shops.
Zune didn't displace iPod - dropped
Windows Phone didn't triumph over iOS/Android - killed off
MS Stores didn't manage to replicate the attraction of Apple Stores - shut down.
I'm not saying MS should keep pumping money into failing projects, but fundamentally there's been nothing wrong with some of MS's killed-off offerings, but MS still seem to believe they can just be number 1 at everything without trying. Instead no-one now wants to commit to any part of the MS consumer eco-system knowing that odds-on MS will lose interest and drop it within 12 months.