[ThreeFx]

99% of the time the answer is speed. It's just way faster to evaluate and build all of this at compile time than at runtime.

I understand both sides of the argument here - on one hand you have fast and unreadable code and on the other hand slower and more readable code. The problem here is 1. the leaky abstraction of characters and code points and 2. loss of type safety due to C's weak typing rules, which is a bit lost in the "hurr durr messy code."