A lot of people speak English as a second language. As a consequence, native English speakers are tolerant of error and capable of understanding an extraordinarily wide range of accents. This is less true for people whose languages are not spoken by as many non-native speakers.
An American who has worked in Denmark recently reported to me the following conversation.
Dane: My mother was a migrant, you know.
Dane: Oh yes, she came from Germany though she lived here almost all her adult life.
American: I see.
Dane: She never learnt to speak Danish.
American (surprised): She didn’t? But how did she manage her day to day life? Schools, shopping, socialising?
Dane (surprised): Oh she could write Danish and speak it but she always had an accent.
People, those are high standards.