It's annoying when people are too thrifty.
Willy has a lot of coupons which can be applied to the same item with the right strategy.
Willy wants to save money.
Willy decides to only use one coupon since there is a line forming.
Willy holds up the line at the store by getting the clerk to apply every coupon he has.
The people in the queue are happier to have a shorter wait time.
The people in line are annoyed with Willy.