Wouldn't this be the policy of Mark Burnett's production company, of which Martha Stewart is an employee?
I'm not sure how it has all been worked out, but this is one possibility.
I doubt she's an "employee." Probably an independent contractor. But either way, that makes no difference. I think Burnett can smell the money, and she knows it. She could have made allowing ex-cons to try out a condition of doing the show. She didn't b/c she doesn't care about them. She's a phony--a limousine lib, like Schlussel said, IMHO.