"Toxic masculinity" was a perfectly reasonable concept when it was originally defined as a
kind of social norm. If we interpret "masculinity" as "behavior socially expected from men", then this trivially extends to "toxic masculinity" as "toxic behavior socially expected from men". For sociologists in the early 2010s, this was a great idea and collected a lot of harmful social expectations under a convenient label.
The problem is that a lot of people, many of them journalists and "influencers" writing for a lay audience, decided they could just cross out the "socially expected" part, which results in a completely different concept that puts the onus for the behavior entirely on the individual — hardly a socially enlightened perspective — and that amounts to the appropriation of academic jargon for the speaker's use as a rhetorical bludgeon. And sure, a lot of these writers were left-leaning self-described feminists who may have assumed they could do no wrong. And yes, many of these term-abusers would go on to propagate real toxic masculinity while decrying the failures of the target of the week from their position of presumed revolutionary thought.
But don't blame the sociologists. They used a reasonable term to describe a real problem. And now they've had to go pick a new term — I think it's something like "male role behavior syndrome" but I don't remember exactly.