Why do MS think they have a god-given right to every Intel CPU?
Also it makes no sense that they are hit by a PC downturn if there are browser, mobile, and tablet versions as well.
The real reason is there's no need to buy Office any more for your home PC or other devices - if you want to use Office you can take your work laptop home, or install one of the copies of Office you're allowed on your work account, or you get the home use program version if your company allows, or you get the education version if you do evening classes. In their effort to dominate everything, Office for outside of businesses has just become a free or very cheap extension of the Office you're running at work or at school/university.
So much for that idea, Satnad.