Earlier quoted context omitted.
Altruism and PR aren't the only options. If the explanation is "they'll be less likely to dare to ask for better treatment" then I think that's a problem.
And that's everyone but Amazon's fault, in this case.
But note that they didn't hire ex-cons when not doing so helped them in their power struggle against labor. It was a thing that only happened when unemployment level dropped to the point where labor had a little bit of bargaining power and not at all before. That's a fact that won't be explained in the spin. I'm sure the Washington post will be all over it in their reporting though.