Your numbers are way off. Its more like 60% pirates, 40% legit game buyers.
PC gamers are the red headed step children of the gaming world, who are convinced they are the master race and us console gamers are peasants.
I personally dont care if PC gets the game or not. They can have a turn a year later to play GTA V once us console peasants are done having our way with it. Sloppy seconds for the gaming master race
Also, PC gaming doesnt bring in big profits for gaming companies unless they can sucker them into paying monthly fees to play online. GTA V doesnt do that, and so because theres no major profit there, PC is not a priority or worth much consideration. Simple bussiness economics.