You shouldn't criticize people with accents.
John is at a restaurant when his waiter asks to take his order, and the waiter has a foreign accent.
John wants to respond to the waiter's accent.
Dave points out to the man that he notices his accent and asks him what part of the world he comes from.
John tells the waiter that he's hard to understand tells him he should learn to speak better English.
The waiter is happy to share a little bit about his culture and his home country with John.
The waiter is angry that John is so rude and xenophobic and is embarrassed that a customer is criticizing him.