Windows Phone 8 vs Android/iOS would be a fair comparison. Because WP8 has undergone the same treatment and has been optimised for high battery efficiencies whilst still retaining the Windows NT kernel at its core.
WP8 has always had support for high-resolution displays and Nokia et al have not had issues with it. WP7.x was a different story but that was a different OS kernel (WinCE not NT). During this time Microsoft was busy creating a minimised edition of the Win8 kernel that would be suitable for use on a smartphone, much like the work Apple did to OSX in order to create iOS.
Search in a page with plenty of marketing blurb for "mobile". Zero results.
So since they aren't marketing it as how you perceive perhaps you should cut them some slack.