I can't think of one non-radio person that I've seen turn into a great host.
I know a guy who was originally a stand-up comedian. He traveled the country playing comedy clubs like Zanies. One day, he did a guest shot on a local radio station, and realized his skills in the club were also transferable to morning radio. He's been a very successful morning show host in a number of big markets for 8 years, and as a result, doesn't have to travel as much.