Oh but it does and often on True Flame. There are absolutely no mechanics in game that prevent multiple groups from stacking. There are no mechanics in game to regulate vested interest in faction or campaign. Hell, we have all often speculated how many accounts with multiple faction characters on the same campaign simply log in one to push and then log in on another to defend. This madness is all part of the ESO experience that ZOS has created. We as players do not have to try and regulate our play or play style based on the lack of the games ability to deliver what the consumer has purchased.
LAG is a result that can only be fixed by the designers and should never be coddled by the consumer. The players are not responsible for self-policing or safe guarding the limits of the server, nor are we responsible for policing the community for cheaters (not calling anyone here a cheater). We are responsible for consuming the content and gaining some form of enjoyment from it.
I believe we would all be happier if ZOS took a more active roll in policing their own game and fixing the issues once and for all.