If you could easily get jobs with a criminal record there would probably be less recidivism. Making a law that forbids you from not hiring criminals would however be quite stupid. If you embezzle money, ....
If you have committed robbery, drug trafficking, DUI, sexual offenses, etc, we don't want you on our property, as our staff would feel uncomfortable knowing that their safety may be at risk due to having to work with some potential violent criminals, let alone trying to apply for a position.
We have customers who are schools, many employees need to visit their premises for various reasons, and they also require background checks on agents.
If we send some employee to a school, and they steal something, or commit rape or assault against a teacher or student, it is our company that would look bad.
Therefore, I think the idea of not discriminating against convicted criminals is insane.
Their jail term was their official sentence, but just b/c their jail term ended, does not mean that all members of society should be happy to accept them fully back into the fold with no questions, no restrictions, and the same level of trust as a 'clean' citizen.