Driving for Uber also requires a significant capital investment and risk assumption, so wages could be expected to be significantly higher than the typical low-education job.
Are people buying cars just to be an Uber driver? Or are people seeing an opportunity to make a little money using the car they already own? If people are buying cars just to be a driver, then I would say that is their own fault for making a bad investment.
Whether or not they owned the car previously or not, they are still investing that capital into the business. If they're driving full time with Uber they'll have to replace that car in a couple of years or so, instead of the ~15 years or so of life you can expect out of a modern car.