MS has been trying to break into mobile for a decade, all while Apple, Google, and (for a while) BlackBerry did.
The Windows brand is tainted, even without the debacles of Vista and 8. Windows is everywhere else, and people are either tired of it (even subconsciously) or don't consider it a thing... it's dangerously close to becoming a generic trademark like Kleenex or Band-Aid, except that no one refers to their computers by the OS, if anything they refer to them by the OEM.
MS doesn't know how to connect with consumers for anything other than XBox. Consumer purchases are driven by emotion, but MS tries to sell to consumers with the same tactics and strategy that they sell to business: dispassionate and cost-driven. Hipsters and college kids don't care about that shit.
Also, MS still seems to do product feedback only to validate their own agenda.