Dictionary attacks are incredibly effective. Humans have a hard time coming up with unique passwords.
My Thai business banking system is paranoid and disables autocomplete, paste, etc, even with the security of a physical token), but the one that really annoys me is things like Basecamp - I had to futz around and disable JavaScript for a login to be recognised and prompt to save a password - by default it does an XHR which doesn't trigger the "save password" prompt.