I was under the impression that the purpose of a guild is to have a group of folks that you enjoy playing with and have common goals. It's a good way to share the game with friends and family, in addition to experiencing new adventures and progressing together. Triamala of Blackwater Raiders fears that such actions are seen as cliquish, causing drama amongst the ranks.
In a post in the Guild Relations forum she said that a previous guild of hers feel apart because of cliques and her current guild is facing the same fate. Members of her guild apparently get up in arms if she runs instances together with her husband or other friends. In a later post she admits that she is closer to the officers than other guild members because they've been playing together for quite some time.