I think the main problem is that it's trying to move in a direction of apps, touchscreens, and all that rubbish, whereas most companies (I think) want software that is efficient and productive. At least from what I've seen, linux (and mac) seems to do everything based on commands, and the gui is just imputing them in a user friendly way. This means that it's much easier to script and automate tasks on those operating systems, MS on the other hand has command prompt, but even then it's not always straightforward, and there are some things that can only be done practically via gui and mouse clicks. I did read up on ARM servers, interesting stuff. I think the main issue is building programs that can actually utilise 100's or 1000's of cores simultaneously.