I never understood couches either but a couple of standups should be no different above the bed than sitting in the bed.
I have a 2 place Triton trailer as well as a 10' Haulmark enclosed and I still prefer hauling my skis in the bed of the truck. No trailer to worry about and way better mileage. On top of that, one of our riding spots is very limited on where to put a trailer.
I started off with a simple wooden frame resting on the wheel wells but now, like wumps, I want to regain my bed space and be able to close and lock the tailgate.