The worst part about felonies is that apparently, the average American can be convicted of Three Felonies a Day. If someone doesn't like you and has a little influence, it would be very easy to ruin your life. Forever. Felonies are no joke. Not only is there a loss of voting rights, but as the submitter has noted, getting hired is impossible. You're also not allowed to own a firearm - even if your felonies wee completely non-violent or were a long time ago. Renting an apartment or a house can be impossible. You can't hold many professional licenses. You cannot even get a license to cut hair if you're a felon.
A felony is in general (but not always) a serious crime. There should be some kind of punishment. But once that punishment is dealt... how do you move on with your life? Is it any wonder that we have so many repeat offenders that get out of jail, spend a few weeks outside, and bounce right back in again? It's hard to find a way to make an honest living, find a place to live, etc.
These people are doomed by a scarlet letter. It is one of our modern society's greatest crimes.