That's interesting and not a perspective I'd run into before. I've participated in a lot of remix challenges and sometimes had remixes of my fic that are more popular than the originals, though I tend to think that's more about my remixers writing boyslash after I wrote het or femslash. :D In my experience comments on podfic are pretty minimal and that's not limited to specific fandoms.

Anyway, I consider it a real treat when someone else engages enough with my stuff to respond to it creatively, whether that's as fic or podfic or art or whatever. I once had the nicest comment on a remix I wrote, the author said that when they read their own fic they could always see the seams, were too aware of how the whole thing was constructed, but that reading my remix made the story feel real and lived in.