Consider ebooks. Amazon has revoked and deleted ebooks that people paid for. They've ironically done it to 1984. And I think even to people living in countries where 1984 is public domain.

It's not that they can't treat games like books, it's that they don't want to. And they don't want to treat books like books either; they just don't have any control over the physical object once it leaves their hands. And before everything became downloads, games used to come on a CD, cartridge or cassette, and you could sell that just like you could sell a book, and they were powerless to prevent it. But with everything being downloads and always online, they have that power, so they use it.