Networks are NOTORIOUS for canning projects that the network head doesn't love himself. The only exception to this rule is Fox every so often. And Murdoch is also the only network head who has restarted a series after he made the decision to cut it, when sales of DVDs vastly overshot projections (Family Guy).
But, for instance, NBC and ABC didn't want 24 as they said it wouldn't work. Um, yeah... great job guys.