Yes, it does save time for the back in person. The pull in person has to wait. I guess the pull in person has more time to spare.
When you're at the grocery store, a person might choose to write a check and request cash back from the cashier, both of which take longer than just using a credit card. That doesn't mean they're being rude to the person behind them in line.
In fact, MOM21SON, might not you yourself do something like put all your change away in your wallet, and zip it securely into your purse, before you step away from the cashier's station?
Or, wait for an oncoming car to clear the lane before you turn left--waiting longer than other people might, perhaps, because you feel nervous even if they don't? And you think it's safer?
We're entitled to live our lives in a reasonable manner, and to do reasonable things, even if they do inconvenience other people.
It is not required for us to do things that are inconvenient for us simply to avoid inconveniencing someone else.
Other people are going to get in your way now and then. That doesn't make them inconsiderate, and it sure doesn't make them rude.