The right to file a complaint

We believe, that everyone has a right to file a grievance. If somebody violates your legal rights, the law should legally allow you to formally file a formal complaint. It should then be read, and if it is true, not frivolous, and has a legal base, action should be taken to stop the violation. I even believe preventing a person from filing one should be criminal. It doesn't matter who you are, or what have you done. Many people agree that even inmates, people which were proven guilty of a crime by a court (often by a jury) deserve this right. Minors are not guaranteed by law to be able to file a grievance about their parents. Yet, many ageists argue against it.

How is it argued against

Kids don't know how to file one - then they won't file one. I believe at least one person under the legal age knows how to file one.
Kids will file frivolous one - if needed regulations may be passed to limit the impact. Complaints can be limited to - for example - one a week, and obviously frivolous ones (based on set criteria) may be replied with just a confirmation of receipt.
This law is useless - this happens with the most gross cases of abuse. Proving this would be sometimes easier than proving child abuse.
It strains the system - this right is key in minor's life. A 100$ ticket affect a life way less. Why can the ticket be taken to court, and a minor doesn't have formal recourse against their parents.