(Some - many) men get uncomfortable and even angry when told in any way that women (due to their lived experience) fear ridicule, harassment, assault or rape at the hands of men or, when reminded that because of this they deserve and want single sex spaces free of the ( even well meaning non- pervy) male gaze.
Why? Well aside from the cohort of pervs and incels, there’s the group of men who can’t abide their wishes and convenience not coming first every time, with no regard to anyone else. Then we have the largest group which is the unthinking, uncaring and the clueless. The last group can sometimes be reached if you give them the male prison thought experiment.
They’re asked to imagine how comfortable they’d feel cooped up with a guy unquestionably stronger and much more brutish than them - they don’t know any harm of this particular guy but the guy belongs to a prison gang that is known for carrying out all the rape and assaults.