If that's what he thinks, he should come visit the local ninjutsu school that has a huge, "We are a blackbelt school!" banner, black belt clubs, kids with pum equivalents (black with a white stripe), teens with black belts, and more belts than some TKD schools.Once again, why is this post in the TKD forum, i see nothing specific to TKD here, besides you including poom belts. Is it that you only care about this as it concerns TKD, or do you honestly believe that TKD is the only martial art with kid black belts?
I have visited and joined a few classes to see what it was like. Their adult classes were pretty good and the instructional staff seems to know what they're doing. I watched the kids and juniors (tweens) classes and they are pretty good for the age groups that are in them. The kids and tweens classes are Ishin Ryu based (says the sensei; I've never trained in Ishin Ryu and couldn't pick it out from other karate styles). If I had young kids interested in the arts, I wouldn't hesitate to recommend the school.
But they do have kids under eighteen wearing black belts. For the record, they looked pretty darned good too.