For some people prison is like a dog bite. Once they've been bitten, they loose their fear of being bitten again.
I used to think a better punishment than prison for this type of crime would be having the DL revoked for a number of years, or life. But the fact of the matter is, that most people will continue driving even though they no longer hold a valid license. That's just how our society is set up. So it's probably better to do both and more. Prison, revoked license, fines and fees, parole, work camp and community service time.