Yes, which is why we have laws - to bring fairness to a system that is indifferent to it. And the ability to serve your time and then move on with your life is one of the ways.
I completely understand your point of view and I'd be similarly careful with someone who just got out of prison. Here's the thing: you said you wouldn't hire "a thief" as a warehouse manager, but someone who went to prison for theft, did their time, got out and has been probably more law-abiding than the rest of us is not a thief - they were a thief.
Again, caution makes sense for a recent offender, but after they do their time and don't do commit more crime for some time, it definitely becomes unfair to judge them for it. Unfortunately, most people don't see it this way, they only see a criminal, which is why employment is such a big problem for ex-cons (esp. in the US) and why I believe there should be a "right to be forgotten" at least after some time has passed.
// And hell, I'd love a former thief as a warehouse manager - who better to spot other employees stealing stuff than someone who knows exactly how it's done :)
In the end, you cannot make the universe fair by enacting human laws. Paid or not, mistakes from the past exist even if you hide it under the carpet. Same as you need to learn from history, not to ignore it, this particular history should be available, not hidden.
As an employer I would like to know who I am hiring and their history, good or bad. I have absolutely no problem hiring an ex-convict, but I care what is the crime and what position would make it not eligible - for example I would hire a thief, but not as a warehouse manager. In fact, not knowing about a potential problem is a bigger problem than "being unfair". I believe in redemption, but not in "born again".