My experience with WoE is not as rosey as yours. We've managed to get a few runs going as a linkshell without any "helpers", but the vast majority of our attempts involved some random person entering to "help" us. They were all a burden to our group. The most annoying one I remember was a RDM/NIN chasing around a mob we were attempting to kite, hitting it with joyeuse and feeding it TP. More annoying still, since these "helpers" didn't listen to orders from our leaders, they could do whatever it takes for them to be valued more highly than the rest of our members, so they almost always got one of our finishing chests when they were actually making things harder for our group. They would lot the random drop coins(ALL OF THEM... apparantly they were making every type of weapon), making it harder for us to reward our linkshell members.
Most annoying of all is that these random people who were leeching off our linkshell's abilities would get NOTHING if organized groups didn't go. They were parasites who fed off the very life force of their hosts, and I'm glad the game is no longer rewarding this kind of player.