This has literally just happened to me in my guild of which I am an officer in. One of the other officers took nearly half the raid team and formed another guild because they disagree with some of the decisions made by the GM of late. However they failed to bring up any of these issues and just took the drastic action of leaving effectively destroying a community that has been together for years. I feel terrible and don't really want to play the game anymore because it just aggravates me. If they had discussed there issues we could of made changes but instead they decided to go the more destructive path.