Always sad to see a guild disband because people take things too far. Your guild should be a place where friends can talk and enjoy the game together and share ideas and thoughts and tales. In my opinion, guilds are all about friendship and unity, IC or OOC, and they shouldn\'t be ruined by outside groups of lamers.
I think you should stick together, no matter what. Nothing is physically able to force you to disband, so you should utterly refuse it in the face of any trouble. If your people are willing to stick with it, then you should not let them down. Ever. Because they are your friends, and they as a guild rely on you. Who cares what a few of pre-teens on a powertrip are saying or doing? They have absolutely >ZERO< influence on anything. Forget about them- your guild is about you, your members, and your FUN. And the sooner you realise that, the sooner you can just start enjoying yourself.