I'm not sure where you are in Michigan but that is certainly not the case here. Used CUTs of any brand are hard to find and, if they have low hours are priced surprisingly close to new cost.
When you do see one such as you describe, I think it is just a sign of American affluence. People with small properties buy them, find they are very effective at taking care of tasks, but they only need to use them for 20 hours a year. After a few years they sell the CUT and buy a zero turn. I have 4 acres that needs a lot of work and do a lot of jobs for friends and still average less than 100 hours per year.
Or maybe just a mismatch. If you've got 2 acres, a zero turn may be the best fit. If you've got 20 acres, perhaps you really needed a 35 HP tractor.