Because they've canceled Dead Like Me, which is easily one of the best shows on TV right now and definitely in the upper echelon of all-time shows. Why? I thought the whole point of cable networks -- and especially pay cable networks -- was that they didn't do stupid shit like yank great shows off the air in their prime. Sure, Fox can do that, and so can NBC, and, well, just about everyone else, but the cablers (to use some lame-ass Variety terminology) are supposed to have slightly better sense.
Anyway, apparently MGM (who produces Dead Like Me) is now looking for another network to air it. Probably just so they can sell more DVDs, but you don't always need a good reason.