I've never understood this. For most games by the time they release on PC the hype has died down and they get a tiny fraction of the sales they would have gotten with a simultaneous release.
Rockstar was very open as to why: PC players are a fraction of a fraction of their income. Xbox One players (yes, the previous gen) give them more money than PC players for GTA Online.
Unlike consoles, general purpose computers are designed to be operated with a keyboard and mouse, not a controller. Yes, you can use steam in big picture mode, but you still have to launch it.