Maybe JPL is better at public relations (getting the message accross) better than NASA because it is managed by Cal Tech... already in the business to educate. Although JPL is funded in large part by NASA. Of course achieving great things are at the heart of scientific discussions. For JPL it was Galileo, Voyagers, et al. For NASA as a whole, it was Apollo, the shuttles (satellite delivery and lab work) and now ISS. Human spaceflight is still associated with NASA. NASA definitely needs it's own public 'channel' to inform and educate. Maybe JPL could lend a hand there too.

One thing is definite, NASA needs it's own (a la C-SPAN or even PBS/sell DVDs, books to help fund it) television channel.