What about usability? "I wasn't too worried about not being able to remember the few function names." certainly indicates that usability decreased. That may have set a pattern for it getting broken, eventually.
This. I was implying that length of the string should mean length in characters, not bytes. This could lead to broken code and would require programmers to keep in mind both.
I have switched from php long ago, but remember odd naming conventions and frequent switch of parameters.