They last a long time because most people forget to adjust their rear brake shoes. This is done by bringing up the e-brake one click and backing up and hitting the brakes somewhat hard several times while moving. Do this about every 6months or so depending on how often you brake. The rears should engage before the fronts putting less wear/tear on the fronts and you won't get that nose dive everytime you brake.

I've seen new brake shoes with only a couple mils of pad on them. They usually don't wear evenly either. The more often you adjust them, the more evenly they'll wear.