IME you do find men who can be convinced, and some of them have become my best friends. But I'm sympathetic to harsh moderation of feminist e-spaces, because it's a numbers game -- you get flooded by tons of men, most asserting the same tedious deflections. Maybe you convince 1 out of 20 -- you're still deluged by 19 shitposts that detract from the theme of your discussion. I'm brand new to this site and one of the biggest free speech zealots you'll meet, but it seems sensible to allow mods of niche subreddits to moderate in favor of their niche themes.

Also, the men I've been able to convince over the years, or with whom I've been able to find common ground, generally distinguish themselves as uncommonly bright and thoughtful from the start, even if they strongly disagree with me. They're not posting 110-IQ manosphere copypasta (which is most of what feminists need to moderate).