Loyalty is dead. Not because I declared it to be but simply because it is. When I was a wee gamer during the days of muds and a while after right until the advent of the more modern MMORPGS guilds were so much different.
You joined a guild practically for life, guild hopping was frowned upon and would generally get you permanently unguilded if you did it too often.
People were invested in their guilds, would rise up to pick up tasks, throw themselves with dedication at whatever roles they got and were generally 'happier' people for it.
Sure there was drama, sure guilds fell apart but there was very little motivation to get up and leave a guild unless it was completely non-compatible with your playstyle in which case you wouldn't have joined it in the first place.
WoW seems to be the complete opposite. People join guilds as long as they feel like sticking around and will happily switch if they even get as much as the prospect of more short term gain. The people that want power generally only seem to want it so they can clean out the bank before they leave...
Just the other day we had someone leaving to join a 25 man raiding guild. Now I know for a fact we are knee deep in kara and have good relations with another guild that's past kara but has manpower issues so it stands to reason that we are maybe a month or two away from doing the first 25mans ourselves.
And here is exactly where my understanding ends.
Why would you choose to leave a guild in which you have already built up good relations and a decent name for yourself, where you have a solid if not guaranteed chance to end up on the raiding roster for kara and 25-mans in the future, for a guild that offers you the chance to raid a 25-man now but in which you have a decent chance of dropping right off the raiding roster if you're not good enough.
It's practically guaranteed that someone will know you're a guild hopper and as a result you'd be hard pressed to find any real support in the new guild you're in. In which case you sacrificed your good reputation with an entire guild for a single 25-man raid.
Maybe my views are skewed... or completely outdated. But I really don't see why anyone would pursue short-term goals if you can work towards getting a better position in the long run instead.