Are set in their ways - Idioms by The Free Dictionary
be set in (one's) ways (redirected from are set in their ways)
be set in (one's) ways
To be inflexible or unwilling to change. Grandma will never retire—she's been a teacher for 50 years and is totally set in her ways. You'll never convince him to change, he's too set in his ways now.
be ˌset in your ˈways be unable or unwilling to change your behaviour, habits or ideas, usually because you are old: He’s too set in his ways now to think about a career change.