"In 1999, Mitnick pleaded guilty to four counts of wire fraud, two counts of computer fraud and one count of illegally intercepting a wire communication,...
He was sentenced to 46 months in prison plus 22 months for violating the terms of his 1989 supervised release sentence for computer fraud."
I would have SERIOUS trust issues with a company run by a convicted hacker.
It's all different today, but Mitnick is old school.
The rest of the security company founders who were active in that era but do not have felony records...by and large, they just didn't get caught.
Which sounds like it might be a reasonable criterion for judging skill, but the scene was so tight and inbred back then that getting caught often had more to do with who your friends (or enemies) were, than with your own skills.