Their official explanation (circa 2008) was basically that the PC was becoming an unprofitable platform to develop sports games for.
Take that for what you will. (i'd assume pirating concerns)
Yeh this is BS as Football Manager 2014 is selling phenomenally. I think it's more due to the fact that if they put out one game people would just mod it and no one would buy their yearly installments.
It's weird that they rarely put any sports games on PC. I'm sure it would sell well enough, but I guess there would be some consumer issues like the company would probably do a straight console port locked at 720p and 30fps with no modding tools. Then when it doesn't sell as well, they'd cry piracy.
I belong to the blank generation - Richard Hell http://www.last.fm/user/akuma634\