I mean, Valve doesn't mind either. But publishers are against it.
Yeah, Steam clearly didn't try to get them to take any games off, but some game publishers did. Epic gives the same "titles that choose to participate" speech but just decided to make a celebratory PR statement over it, where Steam just didn't even act like it's their decision, it's up to each game.
The fault lies with Nvidia, they had a good shot but allow publishers to fuck it up so they don't lose support for their GPUs and shit. They should make it clear it's like any cloud drive/onedrive/whatever service, they don't broadcast other company properties but just provide a remote gaming PC.
Publishers don't need to know whether the used PC is mine, borrowed from a friend, rented, whether it's in my house, at an internet cafe or on the other side of the world. It's still me using my accounts and licenses, it only allows more people to play (and so buy) the games in more situations.
Google and Microsoft and other cloud drive providers don't have to buy all movie and music broadcast rights if I store my own licensed content on there just to let me access it. Some game companies now putting EULA terms about cloud streaming and shit doesn't make it legally applicable.