[masterzora]

> Would you design mathematical notations based on the opinion of 5th graders?

It's not their opinions. It's about how they naturally think.

And, yes, if I could change mathematical notation in a manner that made it easier to learn without introducing a more significant disadvantage, I would do it in a heartbeat.

Things are the way they are for a reason but that reason isn't necessarily that the way things are is the best.