piracy
is exaggerated massively.
This is opinion, but in mine the excuse is used much as the threat of terrorist boogeymen is used to justify various expendatures and security tightening.
the debate is too expansive to cover properly in this comment but I think most agree that most current DRM methods are overzealous and can alienate customers, some of which feel justified in downloading a cracked copy of the game they already purchased to get around the intrusive DRM.
Case in point - legal XP, legal GTA4 = you cannot play this game because you are a pirate. true story, I spent a week playing email tennis with securom about that, finally got the game running after they sent me their own version of a crack. Can you see the hypocrisy here?
Secondly, regarding device fragmentation - this is largely covered by the engines used to develop on, like the Source engine or Unreal Engine 3, and also the *common* operating system the game is developed to run on - namely windows xp, vista and / or 7. Even these OS have built in stuff to handle running a game in backwards compatibility mode.
Not to say fragmentation isn't a problem, just that in many cases the developers themselves only need to worry about it if they are making their own engine.
FYI, Unreal 3 engine also runs on Xbox360 and PS3 aswell as XP, Vista and Win7. Device fragmentation is clearly more Epic's concern here than the game devs.
If there is any reason that publishers don't want to publish games on PC, it is purely because there is more money to be made on consoles. Don't deceive yourself that a few torrent sites have such a huge impact on a global market and have scared the poor little publisher into running to the consoles to get away from the evil filesharers.
Consider that cracking a game only really works for singleplayer these days as multiplayer games authenticate themselves with the server they play on, and that most games have a big multiplayer component. If you want the full experience, more often than not you have to buy it to get it.
If you are really concerned about poorer quality ports on PC, why not just check before you buy and only get games developed on PC?
There are P L E N T Y out there, much bigger catalogue than consoles. I suggest minecraft :D