The danger of "Software as a Service"....
... is that you don't own said software to begin with. It's no longer a piece of code which you bought (in reality: licensed for usage) but it has now become something in the likes of television. Meaning that you have no more control over the thing you're using, because all you're doing is renting it.
And if you don't think that companies would do this: change aspects of something over time, then I suggest you take a close hard look at the PS3 and some of its games (though I'm sure the same can be said about the XBox I'm only using PS3 because I know this for a fact): stuff changes.
Even though I bought a PS3 to play with (so I was happy with the way the PS3 worked - at that time -) they continued to change stuff. Sometimes for the good, but more than often also bad stuff. Like getting a new option for some stupid commercial game ("sing a long") which you can never remove. You can remove the game trial, but that stupid icon always remains.
Lets talk games: I bought GTA V. And I play GTAO (Grand Theft Auto Online) which somewhat makes it a service. Well: one of the things I like doing are gang attacks. You drive around the city, see a red circle and once you step in it a fight can break out and dozens of baddies try to shoot you. Even after R* has abandoned GTA V on the PS3 they still kept changing stuff in GTAO: amongst which the removal of several (popular) gang attacks.
Gran Turismo 5. A racing game on the Playstation. Version 5 has been completely obsoleted so: no more online gameplay for me. They simply disabled the option, gone, p00f: "go buy the new version you cheapskate!".
If all of that can legally happen with stuff you actually bought, then one can only imagine what might go wrong with software you're going to rent. Lets not forget that this is Microsoft we're talking about. These are the "geniuses" which deemed it a good idea to remove the color from all icons in their developer suite (making it pretty much unusable). The same "geniuses" who figured that a developer suite should follow desktop standards, even though there's no saying that the program will actually be used on the same desktop OS.
If Windows 7 eventually does run out of support and no liable alternatives are present (I might consider going Apple though, anything is better than Win10 IMO) then I think I know what I'll do next: I'll probably convert to FreeBSD entirely, while making sure to keep VirtualBox around in which I'll be running my current Windows 7 environment.