Of course they could. But they'd lose the customers buying the PS for the reason that most games won't ever be ported to PC.But what about games that can't be played on new Playstations? If I remember right, PS4 can play PS3 games but not PS2 - so couldn't Sony start converting those to PC? Once they stop selling PS4s, could they start porting PS3 games? (Or even PS4 games if, for some reason, there's no backward compatibility at all.)
Of course I have no idea if would actually be economic. We'd need the numbers and predict customer behavior. I just wanted to say (for the last time I promise ) that there is a reason not to port games on PC.