I think this is just groupthink mixed with the fact that no other place do we operate like we do at bars where we just casually walk up to the general vicinity of the register and wait for the customer service person to come to us as opposed to the other way around.

Patiently queuing is the natural, organized way of things in nearly every other aspect of life when it comes to goods and services, so it only makes sense that younger folks who haven't regularly been to bars to drink yet would do the same after every other place they've been to in their life so far has insisted on single-file queuing in order to pay for things.

Alls to say, we all had to learn these unspoken rules at some point. Give the young people a break, we were all there at one point or another 😊