Because someone cared enough to make it.

(Serious answer.)

But I think you're really asking a different question than the one your words say. I suspect you're asking why someone should bother to write this. There are several possible reasons. "Just because they felt like it" is a perfectly fine reason. "Because they thought it was interesting" is pretty close to the same reason. "Because they thought the world needed this language" is probably not as good a reason, because it seems somewhat unlikely to be correct.