Eh, it's better to be an "insufferable brat" than to be someone who suppresses their personality out of fear... or worse, not really knowing "who you are" because you weren't allowed to express nor enjoy yourself without being scolded by nitpicking, annoyed parents.

I mean, these aren't the only options/perceivable outcomes. Teaching children boundaries and to be considerate of others, or allowing natural consequences to happen when they make poor decisions creates well-rounded individuals who know they're not the centre of the universe.

Teaching kids to be considerate creates people who others want to be around. That in no way requires "repressing their spirit".