this is a important question. I know DCs have all discs but you haven't mentioned what you have.

Disc brakes don't have springs in them so once you let off the pedal the brakes pads pretty much stay where they are, so when you hit the brakes you aren't really moving anything, you are just applying pressure. with drums there are springs that pull the pads(shoes) back, if an adjuster is not working that distance becomes greater as the pad wears increasing the travel of the pedal.