Being from Hamburg I've heard that a lot. Too often, really, to not have an ounce of truth to it. OTOH there are barely inhabitants of the town who have any deeper roots there (ie. their grandparents grew up there), so I'd argue that this is not an original cultural quality. "Locals" is a really broad term here, because actual Locals are either gentrified away a long time or if they were able to weather the gentrification, they usually ended up in the posh islets, to which I'd wager you didn't have much contact with.