Not sure what size tractor you're considering, but one nice thing about the SCUT and the like is the ability to take a 3-point hitch and various PTOs. This opens the range and utility of implements greatly. You see a lot of ATV accessories for this sort of thing but they are often based on sleeve or receiver hitches so you don't get a lot of controllability with them.
One concern I would have is in the low end torque and stress. Tractors are designed with drivetrains designed to do their work at slow speed, so either the gearing is very low or the engine drives hydraulics for hydrostatic transaxles (our little dude uses a Tuff Torq K92) that won't overheat when plowing and tilling.
I'm not familiar with ATVs to know if they can handle being run at walking speed for long periods under load, so it might be a total non-issue.
'91 Pickup - Imelda
'08 Tacoma TRD - Donna
'09 Kawasaki KLR650
'12 Gunnar Rockhound 29
"To live is to suffer, to survive is to find some meaning in the suffering." -- Friedrich Nietzsche