He says, that's because so many interviews on radio take too long and aren't entertaining, which must be the table stakes for any content to get on air.
Just a testimonial to what I stress all the time about prep:
1. Everyone is worthy of an interview, because they can have brief moments of relevance.
2. Old prep can be new again, with a good edit for brevity sake.
3. Questions of the moment can always find a moment in time again.
4. Recycle all great prep, because if they haven't heard it....it's new to them.
The key to creating compelling content is recognizing those "brief moments" at the precise instant and having a system to locate the right voice for it immediately.