They didn't really disrupt the flow of traffic. People walked around them quite fine. That guy in the cart could have gone around too, look closer at the video.
They make people smile, and they make people think outside the box a little bit, BOTH sorely needed in these days of routine bovine dullness.
The people who do these things are everyday folks, who want to be part of something different.
Why bash something just because it's not your thing? Go join up with those that bash keeping snakes because they aren't cuddley. Or tell all of us that the money we spend on housing our snakes should go to charity instead. Those people do the same thing, they take something THEY don't enjoy, and declare it useless and wasteful.