Agreed. In fact one of my biggest arguments against the design is that it will NOT appeal to the average truck owner, because the design gets in the way of the utility. For example, a lot of trucks have toolboxes on the front side of the bed. Due to the triangular sides that pitch at the front of the bed, you can't reach into the bed there from the side of the truck. That's already a nonstarter for a work truck. Another thing is bed rails. The triangular design again prevents the installation of horizontal rails that keep things relatively level. Same story for a roof rack. It's nearly impossible to craft a roof rack for this design that doesn't look goofy and ride extremely high.
Look we can argue about stagnation in truck design but there's something to be said about a timeless design feature, like the classic truck bed. I think Tesla misses here and so their main market for this will be competing against off-road SUVs like Jeep Grand Cherokee or Range Rover. The Cybertruck will not compete directly with say, Ford's F150 and the Silverado.