I and my brothers quickly learned is was no good complaining to our parents about perceived injustice at school, such as whole class punishments. They immediately sided with the teacher explaining they must have had cause, or how difficult the teachers task was, or that the unfair punishment probably balanced some unpunished real offence. This did not mean we did not feel aggrieved. I grew up understanding the world was not fair.
In those days schools, parents, other relatives, neighbours, sports and social organizations, and all authorities petty and great were allied to keep kids on the right path. The allies presented a united front.