1. A bed for hauling.
2. The ability to tow.
3. Off-road capability.
If you value 2 & 3 more than 1, a short bed can be very reasonable. Hell, if you're hauling things that aren't dimensional lumber -- for instance, dirt and gravel -- you're only going to get that 8 foot bed about half full before you exceed the weight capacity of the bed.
Meanwhile, if you have kids, not having a second row to throw car seats into is a bigger limitation than having to leave the tailgate down to pick up plywood.
Meanwhile, if you have kids, not having a second row to throw car seats into is a bigger limitation than having to leave the tailgate down to pick up plywood.