Can anyone explain why they didn't make RDR 1 for PC and why this time that will be different? (Not being sarcastic!)
Rockstar is a behemoth sized developer, but they can still only do so many projects at the same time. So their focus is where their hearts are: console development. PC development comes after.
In case of RDR1, the game code was a big mess for the console release. Apparently, they got it to work on PS3 and Xbox 360, but not in a way that's at all port friendly. So it'd take a lot of effort to completely redo the PC version, and they figured that wasn't worth it. Keep in mind that at the time, Rockstar will also have been working hard on GTA5, so they had to choose: put all effort into GTA5, or slow down GTA5 development and allow lots of people to fix a broken-code game and port it to PC where it might do well, might not.
They chose not to port it, and since RDR obviously ages, porting it now is no longer a sensible thing to do for Rockstar. Too little, too late, and their resources are better spent on new things.
I personally think that perhaps they leave the PC version for after, so their enormous teams are kept busy at all times. If you've got hundreds of developers working on RDR2, and then you release it and their jobs are done, how are you going to keep them around? Immediately starting a new project is very tough, and it wouldn't fit with a game development cycle. Perhaps working on a PC version is a great way to keep those guys busy, whose jobs are done at the end of the console development cycle.
I assume that Rockstar has learned from GTA4, GTA5 and their PC versions. The PS4 and XO are far into their lifetime cycles, so Rockstar probably has excellent knowledge of how to get RDR2 to those consoles. I would imagine that the errors of RDR1 won't be repeated, and RDR2 will come to PC. It'll just take the usual year or so that Rockstar takes to port a game of theirs.
We'll see - I am confident RDR2 will come to PC, just at a similar schedule to previous releases. I hope it'll be after a year, and I hope it'll be every bit as awesome as Red Dead Redemption.