in this point you are totally wrong i use it for some years now and same like the sais it is one of the best weapons ever invented. lethal only when you want it... so the perfect difference to a katana for example... you can do a lot with this weapon...
i own two sais and i practice fighting every week with them... they are very useful love to use them as well as i love to use my bo staff and my compound bow (i love bows )