We don't 'make' children eat healthy or do chores, we bring them up by our example, you all eat healthily, your all do your fair share of the chores that need doing. You aren't racist or homophobic, you don't body shame people, you make sure you do mitzvahs not because we must but because we should etc etc. so that's how your children grow up. It's called leading by example something that the military too encourages funnily enough.
Children aren't the same as adults, they don't usually have the freedom to say they don't want to do something and be listened to. Yes they should be doing activities, take the time to find the right one for your child don't throw them into a martial arts class because you think it will instil discipline in the one or two hours a week they are there as opposed to the days, weeks and months they are with their parents. Parents teach their children to dress, talk and use the toilet why would they entrust someone else to teach them 'discipline' and why would a child be brought up without making sure they are confident? Yes have someone teach the maths, science etc but not an activity like discipline.
Discipline is so often in martial arts extolled as this great virtue when in really it means shut up and do as you are told or you'll get press ups. A disciplined child as opposed to a child with self discipline.
Yep so you spend the next lesson undoing the parents teaching, great.
No, I'm saying they are buying into the myth of martial arts ( and actually paying money for it). It's their job to teach their child self discipline and to make sure they grow up to be confident, well rounded human beings who can question the world and do some good. The parents are abdicating their responsibilities in the mistaken belief that forcing children into something that may well damage confidence and lead to resentment is good for them and that as adults they always 'know best'.
The children who get the best out of martial arts are those who love being there and train willingly, that's self descipline. Those who are forced don't learn that, they learn that they have to shut up in class and keep their misery to themselves, they smile and go through the motions because they have to. Is that worth teaching?