Couple things jump out at me from your comment (and BTW, thanks for such a detailed comment):

1) It's efficient: I love me efficiency. If I can get the benefits for less time/work, that's awesome.

2) It's fun: I've always dreaded running--because of the drudgery you mentioned--but having met so many folks who genuinely enjoyed running, I figured there must be some truth in what they're saying. It's interesting that you mention it too.

And one additional comment:

Will always talks about audio books as the reason he gets any exercise or does household chores. Apparently, a good audio book will get you outside and walking/exercising for hours on end; though I really only need it to get me going for about 30-60 minutes a day. He says he actually looks forward to exercise time because that's when he can listen to the next chapter in the audio book he's currently working through.

Do you listen to anything on your runs?