> leaves it up to the called function to sanity-check the input types instead of letting the compiler do it, and basically nobody does that anyway.
You don’t check the input types?
You're reading the sentence incorrectly: "and basically nobody does that anyway", means the preceding type checking argument you refer to is moot. So I insist, I am a nobody (according to this definition).
Btw I don't always sanity check the parameters, mostly at the system edges only.