He didn't say that. He said, "Don't discriminate against people based on their work, as long it's not a crime". and that many of them aren't on that job by choice.
"Not by choice" implies sex slavery, but he doesn't discuss that-- instead he says that they "have to do that, just to live".
Which... who even knows, with the worldbuilding in this narrative. I really doubt that they had absolutely no choice but to become prostitutes, even in this pre-industrial world.
and before someone use "do legit job then" card. well, it's legit job cuz there's demand&supply.
There's a demand and supply for practically everything, including hitmen-- which is directly relevant given the previous chapter. Supply and demand isn't what justifies a profession.
Also he said that its unfair to discriminate against people because of their profession and that they are still people.
That's two different degrees. Someone can easily recognize their humanity and treat them humanely
without having any respect or accommodation for their job. The protagonist does the former but also insists that they be respected for their job as "working people" without special distinction.
The "edgelord" correctly reflected that in his first mockery: the protagonist
did functionally say "sex work is real work", by virtue of the aforementioned. The "edgelord" also accurately reflected the protagonist arguing its societal value, since he talks about how people are "saved" (or "helped"-- I suspect he's using 助ける, here) through their work.
Even the last mockery he makes doesn't come from nowhere: on one hand, it's not the
protagonist that says it-- his take is far more naïve and probably has to do with him relating to them on account of his own being bullied and ostracized. On the other hand, this is an indirect statement made by the framing of the narrative itself. Part of what's presumably considered to be the "discrimination of prostitutes" is the fact that they're effectively ineligible for marriage (and therefore, among other things, financial security after they age out of their work) on account of the shame they would bring to their husbands. The incident that demonstrates this involves a man lamenting about how he had to break up with his fiancée because he found out she was a prostitute (as in, she likely didn't
tell him before he found out). This is immediately followed up with a narration about how they're treated "as nothing more than rotten food"-- nobody near the "moral center" (so, the protagonist, or the prostitutes we're almost certainly expected to sympathize with since their prostitution is repeatedly stated to be "for their survival") remarks that reactions like that of the aforementioned man is something that can't be helped, given what they do.
The protagonist is sympathetic to prostitutes for what I presume are his own reasons, but the rest of the narrative is sympathetic to the prostitutes to the point that it sugarcoats the profession (e.g. the current pimp is inoffensive and jolly, which is at least unusual given what pimps are normally responsible for) and glosses over their path to where they now are in three panels on half a page, being very light on detail and not at all acknowledging potential problems
intrinsic to the profession as opposed to externally imposed by others' perceptions (e.g. they're vectors of venereal disease; a prostitute may end up unwittingly becoming one half of a homewrecking duo, or may insouciantly become one).
I couldn't care less about whether this is "a "current year", liberal feminist twitter activist's fever dream" when it turns out that he was otherwise ironically spot on for how flippant he was.
I doubt they are even a good person who is open minded to even consider your points. An actual bigoted misogynist and a bad person. Don't bother wasting words with them, they aren't good people.
Are
you a "good person"?