Why should we limit it by age? Also, you say that "I think x,y,z." But you do not say why. Do you have some expertise that informs your decision on safety or i

Why should we limit it by age? Also, you say that "I think x,y,z." But you do not say why. Do you have some expertise that informs your decision on safety or is your opinion purely philosophical (based on personal freedom or even Darwin Awards)?