That it’s a real disorder doesn’t mean that everyone who claims to have the disorder actually does, which is the meat of the comment you’re replying to, making your rebuttal a straw man
The comment makes a claim about a proportion of the "noise" around the issue, which implies that a large fraction of the discussion of mental health and mental disorders is from or about people with made up mental health issues. The claim is made with no evidence whatsoever. The whole thing is phrased as dismissive of people's claims about their own internal experiences, which is bullshit.
