I feel that 'rule' is extremely over the top. I have had three kids in karate. From a very early age. To take them to and from the dojo in street clothes and to clothe them in the dojo is inconvenient and has nothing do do with respect for the art. How should this be a 'no-no'? I can accept, and see, that wearing your belt outside of the dojo may be considered a rule, but your gi? That's just over the top.