PHP is mostly a static language; it has more in common with Java than with say Ruby.
> prefix it with an underscore
Oh god, really. Next you'll be telling us we don't need namespaces, we can just use an underscore as a separator!
> and say "the results are undefined if you call methods that start with an underscore". Done. Easier to maintain, easier to test, less code to type in.
Or you could just build that all into the language itself so it's self documenting and provides a nice concise error message when used incorrectly!
I'm amazed that people would argue for naming conventions over actual features. Hell, nobody is saying you have have to use it; if you'd rather use underscores the languages will let you.
