Sony's decision to stop selling physical disks for its games makes a certain kind of sense from a mercilessly realist point of view—I'd be a hypocrite if I, a person with the majority of my games on one platform (Steam), shook my fist and wept for the end of physical media.
But aside from the sentimental concerns—which, honestly, I don't hold as any less important, there's more to life than money—there is a capitalist argument against the move, too, for both the consumer and the people who make videogames. If Sony ends physical disk sales, Sony decides how much a game on the PlayStation costs, forever.