Earlier quoted context omitted.
> There are some games which really do sell under "irrevocable license to play" (which, short of granting copyright privileges, is about as close as you can get to ownership for a digital product). Far from it. E.g. excludes resale.
For digital products, that would mean copyright privileges. Else there is no definition of "buy" that applies to GOG sales either.
If you sell me a (copy of a) program, I own it and need no (c) privilege to be allowed to resell it. Just like a book.