We spend time playing PG, not on FB, LOL! (I personally hate FB, but that's just me.)
I think eventually the local players will meet each other, especially since there is only one good park with 10 pokestops and 6 nearby gyms. You can see them parked near the gyms or sitting on benches tapping on their phones (don't think there are many spoofers), but I'm somewhat concerned that a player on a rival team might have a problem if I attack "their" gym and therefore try to be discreet... which does not promote meeting other players.
Maybe the incentive needs to come from Niantic. I read that multi-player cooperation may be required to catch legendaries... so maybe Niantic will figure it out. (Yeah, right).