It is a minority, but as usual such minorities are enough to make spaces unsafe for women when they have official backing or at least tacit acceptance of their behavior. That's what turns it from just a minority that can be dealt with into a structural flaw of the community. The recent controversy about transmysogyny and liberal civility politics on lemmygrad unfortunately isn't the first example of women complaining about their mistreatment on that instance. Just look at the reasoning of the guy you're arguing with - his problem isn't exploitation in sex work or coercive material conditions that pressure women who otherwise wouldn't do so into sex work, it's that he views it as dishonorable to perform sex work. He makes a moral argument against the woman where he puts the blame squarely on the sex worker because he's a sexist pig who poisons a leftist space with reactionary ideology.