From a psychological point of view, blowing off steam online is atleast a responsible method of venting.

It may ruin the tranquil atmosphere some would desire, but atleast these people are able to get their hostilities out in a non physical way, as opposed to bottling it all up and snapping one day at their home/work.

And now that they have split, there are now two forums for these people to go and fight with eachother. So if the fighting isn't very fulfilling in one forum, they could just go and register in the other and start up a similiar fight!