> If they're not in the tutorial, examples, or reference, you don't even know they exist. If you use the header file for documentation, and internal methods are grouped together beneath the terse comment "internal methods," then why are you calling them?

Autocomplete is a thing. Even if there is a big comment explicitly saying not to use a function, if it doesn't show up in the autocomplete window someone will inevitable use the function anyway (and sometimes even if it does).