I don't understand the whole "renting" silliness either
I know when PSN was down not long ago I wasn't able to play a lot of my "purchased" games so saying Gamepass is "renting" is just silly Jr High warrior stuff that they think bothers Gamepass users
I call it "renting" because that word comes closest to capturing what is happening - you're paying for temporary access to something. You're certainly not buying it. Granted, it's not "renting" in the old Blockbuster or Gamefly sense, but you're still purchasing temporary access. Once you stop paying the fee, your access disappears. MS can also pull games from the service whenever they like.
I trust that you know I am not coming at this from a warrior POV. To me, it's just a verbal-linguistic question. The word "renting" seems to cover it pretty well. You're paying for temporary access, and when you stop paying, your access is terminated. That's renting, as opposed to buying or owning.
Is there another word you would suggest instead? "Streaming" is just a method of distribution, so that doesn't cut it. It also misses the point, which is to differentiate the financial impact of renting vs buying - and its downstream consequences on developers and publishers, including MS.
Anyhow, I suspect that the issue is not really the word itself, which seems apt enough, but how it is used and who uses it. People wield it as a weapon sometimes in the console wars. They say "renting" with a sneer, as if buying a game is the morally superior alternative or something. That part is silly.