Most passwords don't matter. The example I always use is if someone guesses my HN password, so what? [1] HN is not my bank. It does not need serious security in regard to my use (not speaking for anyone else). Giving it a unique low quality password is fine. Facebook demands a bit more attention, gmail more beyond that, but neither requires life and death security either.

One reason for no single standard is there is no single level of risk. The other is that standardizing password formats makes cracking passwords more standard.

[1]: Though, I did change the trivial password I was using before first posting the example here on HN