Hmm.. Well, I'm not able to join as many groups as I did back in the day-day (like, 2012), but I think the "bad groups" we see share a lot similar qualities (or lack of quality, perhaps).
People have mentioned being power-hungry or way to complicated with rankings and post order, etc., which drains the fun out of roleplaying. I get that.
But one trait that bothers me in a group is a leader who expects their RP to do everything for them once recruiting is done. For one, a lot of users on this game are certainly younger, and so this issue can be attested to inexperience. So, it's not the worst thing in the world, by any means, but it is one of the biggest killers of RPs.
Roleplays thrive on two things:
1.) Members
2.) Roleplay!
A lot of users are good with #1. They'll sit at Stone Bridge of at Cape Portal for hours, recruiting new members left and right. Which is a good thing! A group isn't a group without members.
However, once recruiting is done, too many leaders have either a.) Spent too long recruiting, so they have to leave, or b.) Don't see RPing immediately, get bored, and leave.
And, in my experience, if the Rp leader isn't there, the group itself may RP briefly, but they'll eventually leave. If they leave, and the group continues this trait, the lack of roleplay will bore the new members, and they will leave. After all, they did come there to roleplay.
That said, I practically swear by this particular form of recruiting, to remedy the situation for leaders who find their members leaving:
First, don't recruit for more than an hour. People have to be patient while you recruit, but if you're sitting there for 2-3 hours recruiting, they're gonna get bored and leave.
Second, once you've recruited, get some roleplay started, with the leader there! Every time you recruit! This gets new members hooked on the storyline, or starts new stories. They actually have a leader there if they need to get more members as people trickle offline, and they feel secure that they have someone there for guidance for stories, etc. The rankings do indeed offer some plot points, as well. Interest is key. Without interest, people will just leave.
Roleplay every time you recruit, and members feel that they didn't wait to be disappointed. Plan your times accordingly, group leaders, this way you're less likely to run out of time, too. Recruit early in the day (4-5pm EST is ideal, for example, during peak hours), and then try to RP for an hour or so afterward. More members stay this way.
But, if a leader and its members leave 20 minutes afer recruiting, then it's likely that more of your members won't come back.
Not many people figure this out, though, and so that's why so many groups simply disappear into oblivion, and become the annoying "Ugh they were gone in a week" type of group.