> How do we know it's automatic without knowing the quality of each request?

We don't need to. Based on what we already know, through years of news, abuse, etc., it is entirely inconceivable that every (or nearly every) single request is the perfect paragon of thoroughness and reasonableness.

> If it's a rubber stamp, why are any rejected?

Because no one actually uses "rubber stamp" to mean that literally every single thing goes by, unquestioned.