Parkour is, essentially, play. I mean, a lot of the training I do is at playgrounds. A lot of the stuff we do is playground games: hot lava, PDQ, tag, etc. And even if it's not a structured thing like that, climbing around on our environment is really just play. And as we age, sadly, we are discouraged from playing. So to take up karate or even skydiving, as an "over 30" is considered 'cool' and 'staying young' by our peers. However an activity that looks, acts, and "thinks" like playing, no way.
I know what you mean about the looks. I have some close friends my age, early to mid-30s, who are very "young at heart." In other words, while most of our peers are getting the suburban Legoland house and the beige job, these friends of mine are still dying their hair, getting tattoos and piercings, and playing D&D. They also have steady careers, a mortgage, and a 401k, but they are not letting these things define them and they are doing a lot to "stay young" (for lack of a better way to put it). I thought of all my friends, these people would be the most understanding of my taking up parkour, and would even be down with trying it with me. But no way. They just sort of laugh it off, like, "Oh, sure, Muse. We'll see how long that lasts." I showed them B13 and was going berserk the whole time, and they just didn't get it: "It was an okay action movie, I guess."
'Okay action movie'?!?! It's David Farking Belle! He just did the most magnificent, exquisite speed vault you will ever see in your lifetime, and that's all you can say? Doesn't this movie make you want to go out and TRY that stuff?
They just rolled their eyes.

>le sigh<
Honestly, though, I think it's because society makes less room for unstructured play in our lives as we get older (and sadly that "bottom age" for unstructured time is getting younger and younger), so not only is it frowned upon and seen as less "adult," but people actually don't know how to deal with unstructured time anymore. It makes people edgy and uncertain.
An interesting anthropological point, Cpt.
