Valid points about the tractor. But you may be forgetting that not everyone has a place to store a tractor and an atv and a truck and a car and a mower...etc. plus not everyone has the means of transporting a super heavy tractor as compaired to an atv. There needs to be a balance here. Im not going to find a cheap old tractor then have to find a place to store it cause 99.9% of the time it will not be used. And then i need to buy a bigger trailer and store that somewhere. And upgrade to a 3/4 ton truck cause (just like the atv pulling a disc) my half ton truck will get used and abused pulling the tractor and big trailer to the farm and back.
Plus a tractor is not easy to take through the woods. So ill stick to using my atv and pulling my spring harrow.