It's much easier to load motorcycles pointing forwards, just because you have to get them up a ramp into the bed. In the forward direction, you can use their engine to get up the hill.

It does checkout that people buy bro-dozers to avoid being slightly inconvenienced. Sucke for everyone else who unfortunately have to deal with their rearview mirrors perfectly line up with those headlight beams, unless they also buy a 'dozer.