Having driven a carrier onto these trailers myself, I can tell you that it isn't fun in the least.
The angle of the bed although not looking terribly steep is difficult to climb especially when trying to aim accurately to load the carrier evenly in the centre of the bed.
Ir requires high rev's in low gear and once reaching the bump stop at the top of the trailer, full brakes to keep you there whilst another person winds the tilt down. And let me tell you this is no picnic.
Plus, the timber deck, when wet has the same properties as a bloody steel deck anyway. So when I carted that carrier back to its owners place and tilted the trailer, it slid right off onto the ground. SCARY STUFF
Therefore, it's much easier and safer to winch on even if it's not a recovery. I guess you could save the drive on loading method for emergency use....like " They're shooting at us, lets get the f#@% out of here, drive that bloody carrier on the trailer so we can go. "