For me RT = ReTarded. It seems Microsoft is more inclined from the top down to worry about Windows branding on everything (and their geeks loving the kernel onto everything too) rather than worrying about end-user experience.
With Windows 8 it's more about EGO on everything. Concerns of devs, users and even top OEMs are irrelevant. It seems they would rather deal with returned RT Surfaces than clearing up the naming confusion. The last time I've looked the mail up still wasn't able to to use the most common mail protocol... and on it goes.
These decisions are hardly rational anymore. It seems to me, that they have developed a tight mantra, which says that the Windows 8 design decisions set-up 12-24 months ago need to be followed rigidly, with no modifcations or fine-tuning allowed. No matter the resulting effects or customer/business partner needs.