Personally I think I depends on the tractor usage. For instance, ag tractors, larger HP units, are designed for tillage, and having the operator higher in the air gives a greater field of view to be able to see all that is happening with the implements. This also allows the operator to be able to run a straight course, which is a source of pride to have straight arrow row crop rows amongst most farmers I know.
On the other hand, orchard tractors for instance, the operator doesn't want to be sitting up high, getting smacked with limbs and fruit. He wants to be lower, probably straddling the hump.
Dropping down into the smaller tractors, I think it becomes more of a design feature, with them (the designers) asking themselves questions like "If we put an open station on this small tractor will the operator look like an adult sitting on a pedal tractor?"
And I am not arguing the other points that were brought up, as I think they all bear some factor into the over design of the tractor. But ergonomics and operator comfort are all part of the reason that most of us bought the tractors we have.
Personally, I shied away from the hump tractors- wanting more of ag tractor - more foot space - higher vantage point feel. I felt more comfortable, but I am a big guy too.
My nickels worth
