First, this is not a good implementation of quicksort. Second, it is not often that people will be implementing quicksort.
I don't have one and I confess that worries me. In trying to teach my children, I have actually grown away from the "this is what the code looks like" to examples. And I commend the site for doing that. 2048 seems like an odd example, but conciseness is the goal, I'm guessing. Still a fun one. (Snake would be more fun for kids, I'm guessing. But that is just a guess.)