It makes sense to me that this person would want you to come back and lead the group even after having complained because it's less work for her if you lead the group and she probably enjoys criticizing someone. The behavior is odd from a logical point of view, but it's also really common. I am not sure what kind of group you were leading, but I have encountered similar behavior repeatedly when volunteering (and so have friends, so it's not just me).

The pattern I see seems to be this:
Person 1 is responsible for a task.
Persons 2-5 are not actually doing the task but have very specific ideas about how it should be done. They complain, but they do not offer to do it themselves. They have no idea of how much time and energy Person 1 puts into the task until Person 1 finally gets fed up and tells them to do it themselves!

I don't know if it is some groupthink thing? Or people not valuing other people's work because they are not paying for it? It's very annoying, whatever the reason behind it.