All in all, I dont see how all the guilds are that much different, but in all honest truth, there are people from all the guilds that would never ever detag, so a merger of entire guilds could never happen.
Every guild is different and people need to find the best fit with their RL, playing style and other issues of importance to them. For me, having a healthy balance with RL is paramount, and that is one of the core values emphasized in our guild. We don't pressure our members to do what they don't want, or more than they can.
We emphasize forming friendships, respect for one another, having fun and to do so while progressing. It does not have to be a race... after all, the game is called Everquest
for a reason....
The Horde is a very special guild... and we have slowly grown while keeping these core values intact and our friendships have only gotten stronger over time both with the core members who remain and new members who share our vision.
For me personally, and as one of the founders of The Horde... I made a vow that if need be, I will be the last Horde standing.
So, I am one of those that will never detag.