"Win 10 is touted as "The last Windows you'll ever buy"
"buy" being the operative word.
"Rent" however...
"Windows 10 is touted as the first windows you'll ultimately end up renting to keep using"
I'm sure they've watched how successful Adobe et al have been in getting people to pay every month for software they rarely get benefit of the updates of, and often don't use often enough to make the price worth it but still pay for...
That and it is working rather nicely for them already with Office 365... mugs.