If there was an actual demand for Windows Phone device that would increase their share in the US market, then it would had been obvious to attract the carriers who have 2/3 Of the total market, a market which Microsoft refused to support devices for (yes, I am talking about CDMA carriers and not limited to Verizon and Sprint).
Before anyone says Lumia 922 and HTC 8X, have in mind who will have to do direct support for those devices, and it's not going to be Microsoft unless they actually code for current Qualcomm CDMA standards (more specific to 512bit encryption, standard used currently for CDMA 2000 based EVDO and SVDO). Ironically, no one wants to ask Microsoft why they were not on more CDMA carriers in the US outside the three largest.
BTW, why Sprint is treated as the ******* child on this site?