Thanks a lot, a very interesting read. I agree with you, affordance is a problem as different generations use different tools.

There is also a cultural aspect to it. Recently, I had to find icons to represent the concepts numerical minimum and maximum. This was hard, and not just because the space was limited. I settled on Chevrons (like v ^ ) while fully aware it was not standard.

It is just a way of setting a convention, and hoping your users will catch up to it.