Carriers, like Panther, need to have loads covered. Both good runs and bad runs. Those who sit back and cherry pick, accept only the 500+ mile runs, are, by and large, worthless to a carrier. If you have a 50% acceptance and it's a relatively even mix of long and short loads, they aren't likely to cancel your contact. But, if that 50% consists of almost all long loads, they don't want to mess with you. Sometimes, a 50 mile deadhead for 100 loaded will, in fact, get you to a place where the next load is a good one. You have to take that chance, instead of sitting at home and waiting for the cream of the crop to come knocking on your QC.
Slow and steady, even in expediting, wins the race - Aesop