It might be a factor, but I don't think that's the main reason. If you're an outdoorsy type, you have that immediate common ground with fellow campers, and have a whole host of starter questions pertaining to that interest that will usually kickstart an entire conversation. Same with the marina-goers: boats are an interest that you can start a convo with. Makes it easy.

Funny this is mentioned and maybe there's some truth to it. One thing that struck me about the culture from an extended trip to Mexico City a few years ago is how often people say "hasta luego"/"see you later" for transactions - even if they're total strangers. I found it very warming and a contrast to where I'm from. It makes sense as a farewell but think people take it more literally - to the point where people have responded "uh not really" to my own "see you later".

One of the funniest lines of Dumb and Dumber to me is "well big gulps eh, see you later!" [1]

[1] https://www.youtube.com/watch?v=N_j5tDuakKU