There are uses for a maximum length, but it shouldn't be that small; maybe 255 bytes is a reasonable maximum length, because you might like long passwords. Some

There are uses for a maximum length, but it shouldn't be that small; maybe 255 bytes is a reasonable maximum length, because you might like long passwords. Some of the other stuff they mention there (other than the maximum password length) are problems with the browser rather than the web design, though.