On the other hand, podcasts can be listened to in the background, while text must be actively read. There are pros and cons to each format as a consumer, not to mention differences in production workflow.
If it's something I actually want to learn and retain, I prefer text so that I can go back, pause, skip etc as I please with an intuitive interface - my eyes =)
The same thing with interviews of interesting people I may want to store quotes from. With text it's just C-c C-v to copy stuff to my notes. With audio I need to transcribe it by hand, which is tedious work.