It's true that the level of "group play" is not the same as it was, for example, in FFXI.
That's the tradeoff for being more casual and offer ways to advance without requiring a group all the time.

Something I'd like to see is the return of EXP parties. Not FATE grinding parties.
If SE would make killing roaming mobs with EXP-chain as a group the most effective way of gaining EXP again, I'm fairly sure we would see more communication between players.
Being a member of a FC doesn't mean you can't play with people outside that FC too.