Because of course it is.
The original Red Dead Redemption never launched on PC- but fans were hopeful that the sequel would, given just how successful the PC versions of Grand Theft Auto V and especially GTA: Online have been for Rockstar. So imagine their surprise when, upon Red Dead Redemption 2 finally being confirmed today, there was no PC version in sight.
The game was announced for Xbox One and PS4- but not the PC. This, naturally, appears to have upset a lot of PC fans. So much so, that there is already a petition in place to bring Red Dead Redemption 2 to PC. You can go and sign it, if you think that would make any difference. I don’t think it will.
Because I believe that Red Dead Redemption 2 will be coming to PC eventually- maybe a year or so after it launches on consoles. As I said, unlike with the original Red Dead Redemption, the consideration of the profitability of GTA: Online is a factor here- and given that Red Dead Online appears to be a big push for Rockstar with Red Dead Redemption 2, I say that an eventual PC version is all but guaranteed.