It is rude to be impatient with a disabled person.
Bob is riding the bus to work when the driver stops to pick up a person in a wheelchair.
Bob is in a hurry to get to work and wants to speed things up.
Bob helps the driver secure the wheelchair in its proper position.
Bob loudly complains about the delay.
The bus departs in a moment and the disables rider is appreciative of Bob's help.
The driver has to rush through securing the wheelchair, which leaves the disabled rider embarrassed as well as uncomfortable.