Since the new Doctor Who came back from the dead going on seven years ago, I've noticed a curious thing. I may have mentioned it to you, dear reader, but if not I am now: The episodes don't have much shelf life for me. I watch 'em, I generally *really* enjoy 'em while I'm watching 'em, I even say "Wow, I'd like to see that again!" and then when I *DO* see it again, I find myself drifting off, or thinking "Wow, I loved this before, there's nothing wrong with it, so what's wrong with me?" It's not a bad show by any stretch, but, I dunno, I just don't care about the repeats of the current show, but I still could (And occasionally do) watch the 3rd/4th/5th Doctor's episodes again and again. So whatever it is, it's about the new show only.
I have a similar problem with Lost, but in that case it's because the entire series is a mystery, and now that I know the answer, there's little point in re-watching stuff, so obviously that can't be the same reason here. It's not applicable to Who.
I *THINK* I've got it nailed down, though: I was first exposed to Who when it had a very rigid framework: 90-minute stories, written as a movie and filmed in one block, like a movie (A really cheap one). They had a three-act structure, but there was no attempt to tie up each act into a discrete unit or whatever. Sometimes the ends of the individual episodes were just completely random walking down a hallway or whatever, when you saw them as 30 minute eps. Add to this that my local PBS station ran 'em as 90 minute movies every friday night, or saturday night, or whenever it was. Part of the appeal to me was that it was effectively like getting a new B-Movie once a week 52 times a year. For a dateless wonder like me in those days, what's not to love?
So the old Who (in its main sequence years) had the sensibilities of crappy grade-Z SF films, which I love. The new Who, good as it generally is, is *just* a TV series, with completely different sensibilities. I can watch nearly any movie - even really bad ones - again and again and again and again, I can watch *some* TV shows again and again and again and again, but there's really not all that many of those. Even my beloved B5 is having a hard time holding my interest these days.
So that's my theory. Whadya' think?