Turning down your guildmates can be difficult and even against your interest in the guild. In real life, if your boss asks you to do something because they rely on you, you would most likely help him/her out. The virtual worlds are no different. One's guild leader may ask you to help camp a spawn or partake in a hunt; if the answer is no all the time you will inevitably lose standing with the guild leader, if not the entire guild. Before the onset of online console play, you made all the decisions and had no one, except maybe your brother/sister nagging you to turn on the game and play. Now even Console gamers have this social dynamic seen with Clans. It can be incredbily satisfying to be in a guild or clan and help those you care about, but it can be equally as hard to say no to those very same friends. 

Clans are synonymous with guilds but the term is used for most console guilds. If you are a member of a Clan that is hardcore you better be sure to make the big clan matches. Let your clan down, you let everyone down. It is this mentality that is changing casual games to a more serious, hardcore feel that PC games had exclusively for the past decade. You are now a part of something larger than yourself.