I'm not sure if I would call it sarcasm, but it's a reference to a popular computer science joke format.

The first time I saw it:

>There are 10 kinds of people in the world, those who understand binary and those who don't.

The joke is that 10 is how you express 2 in base 2.

I think there is another layer to the joke, though; often in mathematics, computer science, algorithms, and software engineering, things get divided into sets, sets get broken down into two sets according to whether some property about the elements is true or false, and this joke echoes that.

It's just meant to be silly.