It could just be the nature of the forum. It's pro-choice. But the people it's going to attract are those who are suicidal and want to do it. There are many, MANY websites which are pro-life and aim to help people in this situation. But this is the one website where you can openly talk about being suicidal and talk about methods. It only makes sense that this forum will attract people who want to die. Why would someone who wants to be told their life is worth living or want help go on here instead of all of the other pro-life suicide forums?
It's kind of like if there was a forum for those wanting abortions. You will mainly get pro choice people. There may be a few pro life people trying to talk everyone out of it, but those people will mostly likely receive backlash and get banned. The posters might end up deciding to keep the kid or put their kid up for adoption. But most likely, the people will go on there asking for things like excuses to miss work (so the work doesn't know they're getting an abortion), how to hide it from their parents if they're underage or are on their nsurance, how to protect themselves against protestors, what to expect, etc. Or maybe even how to choose an abortion clinic or how to get it if their state has very strict laws. That doesn't mean the people are against others putting their children up for adoption or keeping their kids resulted from accidental pregnancies. It just means a forum for people who want abortions is going to attract people who want abortions, even if it's a pro choice forum. It would be counter-productive of them to go on a pro-life forum. Same goes for here, but expect it's just for suicide, and it's one of the few places that allows this kind of open discussions.