I think the theory with felons is that offenders tend to repeat at some time or another.
Unfortunately, our current penal system makes recidivism for felons a difficult thing to avoid. Impossible conditions are often tied to parole, and mental illness or substance-abuse issues that may have led to the initial offense are left unaddressed. Certain interpretations of "three strike" laws make it very easy to turn misdemeanors into felonies.
The definition of "felony" is far broader than it was during the founding days. As such, I'm always leery of seeing someone stripped of gun ownership for life over a youthful indiscretion or for writing a couple of bad checks.