I'll hazard a guess here. It's purely, totally a guess.
To do a political based news/talk show, all it takes is some training, a little talent, and some experience. To to a good, effective advice or information talk show, you need those things, plus you need some bona-fide expertise on the subject itself. So, I asked myself, if I had bona-fide expertise on financial matter, like Bruce Williams, what career path would have the best combination of rewarding working conditions and high compensation. And when considering all the different ways I could put that expertise to use, tying myself down to doing a regular radio show was near the bottom of the list. My guess is that most folks with the expertise to do an effective advice show are using that advice in a different arena.