For the past few decades, I've assumed that they don't really have serious users in any numbers that matter to their bottom line; what they care about are their serious buyers, who are large corporations who are basically locked into Windows, and who will continue buying Windows desktops & laptops for their employees to use.
Between Cortana and all of the post-Bungie games, it's almost like they were hellbent on destroying the Halo IP and all of the goodwill associated with it.
