I have Windows 10 myself. But lots of people have opted against it because they see no need for it, or dislike Microsoft's policies - both perfectly valid things. Just because it is "free" does not mean it is a must-upgrade. Others had issues with it early on and thus abandoned it.

Sure. Don't see how that's a valid reason to stay completely on Steam though. In general, all my points here are anti-storefront loyalty. I am fine with you disliking the MS Store. I just want people to try different stores and not confine the market to Steam. You saying Steam/GOG/whatever in the next point makes me hopeful that you use other platforms as well, but the point I was making wasn't that you should use MS Store or anything, but that you shouldn't support Steam as a fan and should support competition in the PC market.

Also, whatever Valve has done pales in comparison to the spying practices Microsoft have put in place since W10 came out, and consumer trust in MS is probably at an all-time low

Wow you fucking fearmongerer. All spying on W10 can be turned off in the settings. All of it. All. A. L. L.

I've only really played W10 Minecraft (briefly, it was awful compared to the regular version) and some of the card game stuff from the MS Store, so I don't personally have much of a point of reference.

Then don't try to argue a point which you are completely uninformed on.

I agree that it is unlikely, however it IS a possibility. Microsoft's apps have proven unreliable (with even the goddamn start menu breaking for many - including myself, on two systems - earlier in W10's lifespan), whilst Steam tends to be fairly stable (and is of course very mature these days - W10 still isn't for some.)

As I said it is a completely valid reason for those that have those struggles, but that is very much a minority.