Once upon a time, it was difficult or impossible to attain certain skills without committing acts which might have been ambiguous then, but are now clearly "breaking the law".

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.

Seems like that would be a good credential for a computer security consultant to have

By that line of thinking, I can't wait for Bernie Madoff to get out and start another hedge fund. o_O

Or to start a company to help people AVOID scams maybe?

Wouldn't people prefer credentials that don't involve breaking the law?

It would seem like he has more to lose and will understand the consequences better than someone in that space who hasn't spent years in jail.