You sign up for ICC. At go-time, the raid leader announces that there aren’t enough people signed up to do ICC, but if we pull in some casual players, we can do a lower-level instance like Ulduar. Let’s say you HATE Ulduar and are tired of Ulduar and just don’t wanna. You signed up for ICC. It doesn’t matter about gear (let’s say you don’t need gear from either instance) it matters that you signed up for X, and now you are about to do Y.
So what do you do? Do you go along with it because if you don’t, you spoil it for the other 9 people who are fine with doing Ulduar? Do you say “thanks but no thanks” and wander off?
You sign up for ICC to continue to work on Sindragosa. At go-time, the raid leader announces that there aren’t enough people signed up, but if we pull in casual players, we can make a full raid. However, you’re not going to try Sindragosa, as originally planned, but instead head to Festergut. Same instance, change of plans in which boss you are going to do.
Has your answer changed? Should it?
The Balancing Act
Essentially you are having to balance the needs of the guild against the needs of yourself. You don’t want to be a dick to other people, but you don’t want to spend your playtime being dragged to stuff that you didn’t want to do (especially if you have limited playtime).
Food for Thought
When you sign up for a raid, do you sign up for the activity itself, and if the activity changes, your sign up is void? Or do you sign up for a time slot, and the guild has you for that time slot, regardless of what you end up doing during that time?
If you sign up for an activity, how much of a change in plans is so much of a change that you are no longer expected to attend under the original sign up?
Does it matter whether some people still need something from the new activity? Does it matter what they need (i.e. a mount versus an achievement?)
If changes of plans were common, would you think twice before signing up for activities?
EDIT: Further reading!
Muradin Musings: Self-Interest vs. Greater Good