Who the hell are you Ruby to speak to what is enough to create a suicide in an INDIVIDUAL that is not you? You can't know what an individual may or may not be able to take, what they have the tools to overcome, etc. True, one thing doesn't often a suicide make, but it could be any one thing that pushes someone over the edge.
I also don't know how you can say that mentally ill people don't join. It happens all the time. People with trauma or mental illness are attracted to them.
I believe that the cult not only attracts but also creates mental illness. Leaving relieved me of so much, and I left so many mentally ill people behind. You are asserting things as though you know absolutes. Your minimization above of them being nothing more than a high commitment group is what is crazy. They're much more than that.
Additionally, asserting that suicide is easily preventable, just go get help and don't escape into detrimental things shows a profound lack of understanding as to how people with things like depression act. They often don't care about themselves enough to get good help or don't have the energy to do so.