You might consider that the reason staff don't realize you can tap is that nobody uses it, because you can just swipe without a PIN for small purchases. I am not saying this is superior, just observing an example of how even changing consumer behavior is difficult when the value add is minor.
Australia has different rules. In the US at least, the PIN is not required for small purchases.
It's interesting you mention Australia because they've taken a different approach to the fee issue. They regulated it away. Cards cost merchants very little. Didn't need bitcoin to do it, just passed a law.
Also interesting: it did not result in a lowering of consumer prices. The merchants kept the windfall.
