[adregan]

I think I’d argue that it’s beneficial in this case to lean towards abstract figures which must be looked up. What the designer calls intuitive, I might argue is actually easier to misinterpret.

One must remember that these are international symbols and the cultural context you bring to interpretation is different from another’s.

[Ekaros]

Also there is very clear design goal with originals for each being distinct from others. Which explains lot of design.