Firstly, the gerund for "die" is "dying," not "dieing." It was a good guess, I suppose, if you'd been from another country.
Secondly, there's no reason for a PC game to be exclusive, considering the XBox 360 is made by the same company that makes Windows (the OS that most PC games are developed for). In fact, people program console games on PCs (because consoles don't have keyboards). So, if you measure "success" by how many games are PC-exclusive, you're digging a hole in the sand for your head to go into. It effectively blinds you to cross platform releases.
Thirdly, the popularity of MMORPGs and so-called Casual Games is on the rise. Ironic, considering what I just stated, but these games are mostly PC-exclusives. Not because it's too complicated to code for a console, but because even console gamers own computers that can play them. There's no reason to attempt to open up a new market if that market already has access to the game.
And finally, fourthly, this is the perennial question that everyone seems to ask, even columnists on the Escapist. It's like clockwork. We get a whole bunch new games, they sell well, their PC counterparts come three to six months later and everyone goes "welp, time to start hammering some nails into the coffin of PC gaming!" except they apparently forgot to find the cadaver of PC gaming first. It's like PC gaming is standing in the corner at it's own funeral going "Hey, um... I'm not dead..." and everyone else is going "it's so sad... You know, if I listen close, it's like I can almost hear his voice..."