Yes, the decision by Amazon to favor U.S. veterans and military spouses will help these individuals, but it will hurt those not affiliated with the military. There will be many qualified candidates who will not get a job offer because they are outside of the preferred group. That's just the reality of the situation.
Amazon's decision to grant hiring preferences to military veterans and spouses will impact individuals that are not in this group. Some people will not be hired due to the fact the Amazon will grant hiring preferences to veterans. Companies are always better off when their hire the most qualified candidate for the job.
It's unfair to give people in the military a hiring preference, because these people are already well paid for being in the military. They often get a pension for it, too. There are people with disabilities that don't have the option of being in the military. These people need to get jobs, too.
I understand Amazon's logic in making this move and it's welcome news for veterans and military spouses. However, there are plenty of other groups who deserve such considerations, firefighters families' come to mind, and those groups now have to face an extra disadvantage. It would be nice if Amazon opened up a training center for everyone and then hired on merit from the trainees.