If I had to say why Twisted Legion fell apart I'd say it was definitely because of the leadership turnover at the time. I quit around PoP when GoD vote failed twice, the reason for this was because I was in my last year of University and the amount of stress I was taking on from leading the guild, mixed with my workload at school was extremely high.
I made what I feel a reasonable decision that my education was more important than Everquest so I gave leadership back to the original creator of Twisted Legion, Zain. Zain ended up quitting shortly after (As he always does). After school was over I came to Fippy only to find the leadership was just a hollow core of people and just didn't care anymore; they had no motivation to push the guild forward. The people that remained in the guild were terrible and had no idea how to play their classes.
The leadership never wanted to call raids to farm Demi, anguish or DoN. PoR release day was what put the stake through the guild when the expansion released, there was very little research done on the raid mobs in ToB and the guild just got absolutely blown up. Few days after that the guild was straight up disbanded.
You definitely need leaders to have a spine with high stress tolerance to play Everquest. The politics, the drama and surreal amount of idiots that can occur on this server or with a raid of even 54 people is obscene. If there's something to complain about, people will find it. The end result is typically the leaders get grinded down to the point that nobody wants to even play anymore. It's super easy to replace people in a guild, however it is extremely difficult to replace quality players and smart leaders.
The worst thing I've seen is when officers stay officers but stop doing their jobs, which forces other officers to pick up the slack. Typically you can't have 1-2 people carry an entire guild and expect it to flourish, I find being a good leader is someone who is extremely good at micro-managing as much as possible. Internal controls are extremely important as well.
Being a strong guild starts at the top with the leadership, having a leader that never goes anywhere is extremely important. Twisted Legion had probably 5-6 difference leaders. Being that I'm done school and have a career I do not intend on leaving the Everquest scene until they officially remove the servers.
Why anyone wants to lead a guild is beyond me, the only reason I'm doing it is because if I didn't, none of my friends would and I enjoy playing games with my bros. I think people should always remember that their life>EQ, you should never ever put EQ before anything important irl.