I remember this was linked on the LeftWingMaleAdvocates subreddit before it was privated. I do not know who made it, but it is an archive of all posts and comments submitted there. The association with the red pill is unfortunate, but this seems like the best way to read the old posts now.
Edit: Seems like the subreddit is back up. https://www.reddit.com/r/LeftWingMaleAdvocates/
I actually saw a decent amount of left wing thought coming out of mensrights, honestly. I think the presumption you’re making is that feminism is the truest form of left-wing thought, and it’s not, and is frequently in opposition to leftism while claiming righteousness for itself.