It shouldn’t be, but here’s the thing. Valve isn’t distributing games out of the goodness of their own heart. They don’t want to have to process refunds for every person who buys it and realizes they aren’t allowed to play it. That’s just a waste of time and money for them. And Sony hasn’t invested in a launcher and store of their own on PC, so they’ve got no choice but to obey whatever conditions Valve puts on the sale of their games, unless they want to pause until they get a storefront up.