If you are thinking of joining a fleet then this is a really good rule of thumb. You want to join with a group that is a place you want to call home. A social group is more of what a Fleet really is. There are thousands out there so you have the right to look around first.
Agreed. When all is said and done, you ought to be able to feel that the people in your fleet are people that you want to hang around with, not just people that you put up with for the sake of the other benefits of fleet membership. If you find yourself in a fleet where you don't like the people, then leave it and find one where you do.