What does Matthew 11:21 mean?

Shame on you, Chorazin! Shame on you, Bethsaida! If the miracles done in you had happened in Tyre and Sidon, those cities would have changed their ways long ago, sitting in ashes and wearing rough clothes to show their regret. Matthew 11:21 - Modern Text Bible

(He says that even famously wicked cities would have repented if they’d seen what these towns saw.)