One thing always constricted that raw creative development: time. Whatever we did had to take place for one hour every Monday morning. Find me a musician in the world that works like that (or an architect, mathematician, dancer, or journalist for that matter)! The creative process becomes secondary to ‘classroom management’. Even if someone did find inspiration on a clarinet one lesson, they’d then have to stop and go to their next lesson, only to return one week later when you can be sure that the moment of inspiration had diminished considerably.
If the creativity was to be the learner’s own, and not mine or the teachers, they would need time to become interested, to deliberate, to experiment, to get things wrong and try again. And not just in hourly slots every Monday morning. The same is of course true of all learning.