Likely because people either move with a purpose (getting retired and living in a retiree community) or are moving to a specific community (an immigrant community, like myself), so there is plenty of other people just like you around.
The community I live is easily 30% Brazilian, my oldest kid pre-school class is 90% kids born to Portuguese speaking households, even the kids that don't speak Portuguese pick a word or two and join in our events.
I think the kids definitely change the equation, it is much easier to find other people in the same life period as you due to the kids being around the same age and being together anyway. Not sure how it would be if we didn't have kids but then again if we didn't have kids we would have stayed in PHL or moved to NJ/NY, we wouldn't come to Florida.