Firstly, this ignores the fact that most crime occurs due to socioeconomic reasons. So you're kicking someone in the head after they're already down and have served a punishment doled out by a judge.
Secondly, obviously the -type- of crime should make things more difficult or impossible in certain cases. But arbitrarily punishing people for having any conviction at all is the opposite of what a healthy society should be doing. This thoroughly ensures that recidivism rates will remain high, because what's the point in trying to cooperate with a society that brands you as a criminal no matter what punishment you serve or what you do throughout the rest of your life?
We need to focus on rehabilitation, not continuing to punish people for the rest of their lives.
"That might not be fair, but that's how it is."
Sorry to be blunt, but hopefully this punitive attitude will die out as older people die out. This is one American attitude that I absolutely despise.