People in the coffee shop are not looking at your children with an indulgent smile, unless they (the people, not the children) are concussed (although they might be more inclined toward an indulgent smile were your children concussed). They are wondering, in increasing frustration, whether you were raised in a barn, and if you weren't, whether you have, for that reason, committed to raising your children in a barn.
There are ways to placate children. If all of them fail, remove the child. Your bad parenting and stubborn children are not sufficient reasons to bother everyone else in the building.
It is actually not emotionally crippling or controlling to demand that your child not be a deafening terror. It is good preparation for later life, if he wants a job that is not "reality television star."