And also, sites that have a limit on password length. And sites that have a silent limit on password length, and secretly truncate it. And sites that have different truncation, depending on which form you use. And sites that require a Capitals, lowercase, and numbers, because nobody would just use name+birthday.

Leave the spaces out..?

Exactly, or if the site requires numbers/symbols those three spots are perfect place to put those instead of spaces.

That's not what is proposed here though.

The point is that one size does not fit all at the moment.

I guess developers need to change the way they handle passwords.