Unprovable people are a liability to Amazon. They're minimizing liability to their business. In their eyes, a broken appeals process might be a benefit. If a would-be customer is enough of an outlier to need a special process, it makes sense to handle them quickly, and less sense to handle them correctly.

In my area, it's almost impossible to even rent an apartment without good credit history, and it's absolutely impossible to rent a non-crappy apartment. Why? Because there are enough people with solid credit histories to fill the buildings, and because of the lower risk, there's no reason not to rely on credit checks.