Re: I have yet to buy anything from android...
In a lot of press it's because the press releases make that comparison, and the press releases more often make that comparison because — as you imply — there's more people that want to make their camp look larger. It's also a much easier narrative.
The technical press probably do it entirely because firms that chose to support Android devices on their infrastructure really don't care whether there's TouchWiz or whatever on top or not, and people who make money through applications similarly either put resources into iOS or put them into Android. Writing an Android application for a Samsung phone is no different from writing one for an HTC phone.
I guess the main people that really want a firm-by-firm breakdown are investors, which are the exception.