Many things are completely arbitrary and yet have weight. Laws. Language. Being arbitrary is not sufficient reason to discard the idea on its own.
It has basis in reality in that it reflects the experience and judgement of many people. It’s a common expression. Given this post seeks the judgment of people, that basis is insufficient to discard it.
(46/2)+7 = 30. 30 is the floor. 25 is too young.
That whole rule is completely arbitrary and has no basis in reality.
Many things are completely arbitrary and yet have weight. Laws. Language. Being arbitrary is not sufficient reason to discard the idea on its own.
It has basis in reality in that it reflects the experience and judgement of many people. It’s a common expression. Given this post seeks the judgment of people, that basis is insufficient to discard it.
Your reasoning is bad.