The abbreviation 'MSM' is very much not neutral, yes. I haven't done a survey, but I do not think it's controversial that it's a term used by certain online subcultures (just like many others from all sides, again I am not picking sides here, it's just that this abbreviation started this whole sub-thread). Feel free to disagree, but I've seen it used in parody/stereotype mocking of such groups enough to know that I'm not the only one who would see it like that.

Likewise, it is not controversial or even assuming to state that explicit tribalism and signaling of affiliation does not make for 'good' or 'high quality' (if you prefer those terms over 'intelligent') discussion. Sophistry is not 'intelligent' discussion. It may require high intelligence to pull off well, but it's not 'intelligent discussion'. I'm not saying which topics are 'intelligent' or not, or what position in those topics is, just that some forms of having any discussion are 'better' than others. It's a 'meta-judgement', if you will. 'Intelligent discussion' doesn't just mean 'discussion between two people who are intelligent and well informed on the subject'.