Should a person convicted of theft, who's served their time, paid the fine, made the victims whole, and learned not to steal, be discarded from consideration as a useful member of society? In case it's not clear, I think they should have the same rights as any other human being.
No one seriously advocates the death penalty or life imprisonment for petty crimes. But depending on the ability of a society to forget (which the information age is rapidly making very difficult) and the ability of a society to forgive (which the climate of fear is also making difficult), a conviction in your record can ruin a life.