Why? Because it adapts very fast to any environment. And if it can’t adapt itself, then it adapts the environment. A good example is the ever ongoing clash between the establishment and this avant-garde that takes place in basically any developed urban space.
Adapting itself
Cops or security guards (who also secure the established order) constantly kick skaters out from spots. But skaters literally adapt their time and are constantly coming back there to do their tricks.

The only way to get rid of skateboarding in urban space is to destroy it completely, and change it into a plowed field. But then, there will be no city anymore, so it will be a radical decline of our civilization.
Adapting the environment
In case there is a complete lack of civilized terrain, skateboarding creates its own habitat. And what do we see then? We see DIY’s, which have each and every feature of a construction made by a developed civilization. There are building materials like concrete, wood or metal. The shapes of the built objects are either typical for urban space (street elements), or consist of the most refined architecture (“the tranny stuff”). Not your typical agro environment, huh?

In other words, skateboarding is truly progressive. And with this, it is a driving force within our civilization. It is the same kind of factor, from which this civilization consists of.