"Anyone with an open and honest question who engages gets lots of helpful responses."
Yes, but only if they are willing to accept the premise of feminism in the first place. As soon as they say they disagree with some of the responses, the insults and belittling starts (in my experience of lurking on there, prior to hiding it).
You only have to look at the Equalism thread from the feminist board that I linked to earlier - it hit 3 pages, mostly full of 'the usual suspects' saying how it was all bullshit spouted by people who accepted the patriarchy and didn't understand how women were oppressed before it died.
Compare that to this thread(s) which have been, for the most part, a useful, informative and generally non-confrontational discussion of the differences and similarities between feminism and egalitarianism and the issues that people have with feminism that mean they don't want to self-identify as a feminist. There is no way, the same conversation would have got anywhere near 1000 posts on feminism, even if you take the anti-feminist bigotry from the start of the discussion out of the equation.
It was on a thread like this one, but on the feminist section that I got (indirectly) accused of being anti-feminist simply because I was not in total agreement with feminism. There was no recognition of possible middle ground, it was all or nothing. At the start of that, I didn't think I was a feminist, but was willing to be persuaded if the arguments were strong enough - I'd only just started my thinking on the subject having previously been more interested in the psychology of identity.
By the end of it, I was fairly certain that I didn't want to be a feminist by the MN Feminism boards collective definition. It encouraged me to go and do a lot more reading around both feminism and egalitarianism, which only convinced me further that despite wanting gender equality and recognising that there was still some way to go to achieving it, that actually, no, I wasn't a feminist and never would be - despite sharing some feminist ideals.