Why 'I'm busy' is the enemy of creativity

I am not sure when it happened, but why did it become OK to reply to the question ‘How are you?’ with ‘I’m busy’? Over the next week, listen out for it. You’ll say it yourself without even realising it. At a guess, I’d say I hear ‘I’m busy’ from more than 80% of the senior creative leaders I meet every week.
It’s as if being ‘busy’ means that you are at your creative, most productive, best.  
This could not be fur