I don't really see why this is a problem. It seems like all this policy does is lead to the hiring of people who seem like more "iffy" hires during the interviewing process who are given the opportunity to work/learn/shine at Amazon.
I can see the point that maybe that employee would have taken another role instead of the Amazon one, but I highly doubt anyone who was "hired to be fired" who then showed they were a great fit/good employee was then fired to fulfil the policy.
If instead of being called "Hire to Fire" the policy was called "Rock or drop" (as in show you rock or you'll get dropped), would this even be worthy of an article? Why is the very idea that someone be given a chance that also comes with the reality that you might not make it so hard for some to accept?