I think doing kata is like taking the slow boat to China.
It may be useful when you're sparring in a controlled setting with another karataka, but if you tangle with someone who is proficient at jui-jitsu, or a good boxer who knows how to distance himself properly, or even a smart street fighter, and try to use kata, you're gonna get smoked, and fast.
That's why a karateka should seek to understand kata.
All I can thnik of is that your view is probably a bit limited as your knowledge on kata probably is. (I don't know.)
I think a boxer will have a disadvantage against a karateka who'll be used to grappling, striking and kicking (all contained in kata), since a boxers arsenal basically comes down to arms (punches).
Smart street fighters?? Someone smart would try to avoid fighting.