It is indeed. Which is why I never said it gets all of the multi-plats, it does get a very healthy number of them, though. As for Microsoft, after realising PC gamers wouldn't pay for its woeful Live service, they stopped making PC games almost entirely (I believe Sony have made more PC games over the last few years than Microsoft) and concentrated on XBox exclusives instead. If I were a Microsoft shareholder, I'd be wondering why they've allowed themselves to be completely blindsided by the apparently massively profitable Steam, while simultaneously pouring money away on the 360.
As I said above, not every game is viable on every platform, and most of the games in your list are very console-oriented. While it is very possible to hook your PC up in your lounge, and play local co-op, it's not that common a set-up, thus many games of that ilk are going to be more suited to consoles and to be played with controllers.
Starcraft 2, The Witcher and its sequel, the Total War series, the Warhammer games, God knows how many MMOs, almost the entire output of Paradox, Civilization, the King's Bounty series- none of these have made it to console. Why? Because similarly, they're not a good fit. They're much better played with a mouse and keyboard and the audience for them is mainly on the PC.
Where the lines are blurred, and games fit both, such as first and third person shooters in particular, then the PC usually gets a port. Piracy really is a red herring, an excuse offered up by publishers to excuse the crap sales performance of their latest game, or to justify their latest anti-consumer scheme. If it was a real problem, then nothing would get made, and given the prevalence of piracy, and especially zeo day piracy on the 360, it would be getting games canned as well. The real problem for a lot of the big publishers is the 'AAA' Hollywood-style business model they have, where even big sales often don't make a game profitable.