I don't know. I think it's because I can still read more quickly in my head than people read aloud. So somehow audiobooks have always seemed like a waste of time.
As for podcasts, my problem with them is the matey in-joke self-congratulatory chatfest they seem to have to start with. Man, it's SO BORING to listen to 10 minutes of who ate what when and with whom before getting stuck into the covenant of redemption.
Then came The rest is history. It's still matey, but at least it's brief and self-deprecating. And then you get horrible histories for grown-ups. Riveting. I listen to short bursts while walking to the pharmacy, to the tram stop, to the supermarket, wherever.
Which brings me to audiobooks. I'm ready to have another go, especially for those times when I wake in the wee hours and need to read until I fall asleep again. I can play an audiobooks through earphones until I hear Morpheus' footsteps, then whip 'em out quick and set sail for the land of nod.