I think when I priced it out before, simply from a cost perspective, the Keurig is 40-60 cents per cup versus 5 cents per cup. So it's about 10 times as expensive per cup. On top of that the cost of the machine is more expensive. In no way is it a bargain from a coffee drinkers perspective, it only is a convenience machine.
It's less mess, convenience is the key part. But definitely, filter without, or whatever is cost prohibitive to most.