This.Cost in my opinion...
Ratchet are the easiest to use, and probably as cheap as to make as ones that use a basic pin.
Screws cost more money to make, and aren't quick to use.
We've got a set of pin ones with screw adjustments at work, but they hole 5 tonne, and cover from about 3-5ft height. I'd imagine they cost a couple thousand for the set of 4.