maybe the real message is women saying: “We are scared of unknown men.”
It's not unknown men, it's alone with men, period. Most sexual assaults are not stranger-rapes; they're sexual assaults being committed by a person that was known to the victim. Often it's an intimate partner, a date, a close friend, or someone that they went to class/church/etc. with. If people you know aren't safe, then how could you trust strangers?
No one alone with no witnesses, at least. And there's the issue, isn't it? It's not, "would you rather be in a crowded bar with a mix of men and women, --or-- would you rather be in a crowded bar full of bears".
Also, most folks are horrible judges of character and intention. Scumbags are usually the most charming, outgoing, and well-liked people, and yet most people think the awkward weirdo in the corner bothering nobody is the 'threat'.