I feel that the way GW2 plays, there's just alot of anonymity for open world PvE (which is mainly what I play). You don't need a party, you don't need another player to team up with, you don't even need a guild. Hop into a meta and there's 50+ people. The only times that I talked to people was when I started trying raids (or a few specific metas like Octovines where you have to coordinate kill), but outside in general PvE, there just isn't really a whole lot of reason to talk to anybody. Its like living in a big city, just another anonymous person going by their business. There's no names in the trading post either so buying/selling is also pretty much completely anonymous, you wouldn't message them to try to strike up a deal with them like in other games.