This is misleading at best. Toxic masculinity has been written about in great detail and at great length in academia (in gender/women's studies literature) for going on 30 years.
Generating literature about a postulation doesn't make it true.
How would you ever controvert a bad practice like icepick lobotomies, or a false belief like Aristotelian gravity, if the simple existence or popular acceptance of an idea were considered to be its proof?
What words would you prefer people use to describe a particular kind of behaviour, common to, but not exclusive to young men that is in generous parts mysoginistic, often homophobic and violent?
That the behaviour it describes doesn't exist? That would be a truly remarkable claim.
That the term is inapplicable to that behaviour? On what grounds? Is there a term they'd prefer we use?
That the behaviour exists, but we shouldn't slap a label on it? That's almost certainly personal opinion, which is not very interesting.
If the OP would have instead said that particular claims about toxic masculinity are false, that would be an entirely different conversation. But that's not what they did.
I rest my case. It is not a legitimate psychological concept.
The article quite clearly says no. Moreover, “toxic masculinity” is a political dog-whistle, not a legitimate psychological concept.
EDIT: ffs don't flag the parent poster. He's misinformed and possibly ideologically driven (though I've seen far worse), but enough with the censorship bubble, already ...