I know this goes a bit off from the article (I skimmed). But I think a lot of this toxic masculinity comes from decades of media on what a American man should be.
They need to be strong, independent, smart (sometimes), ingenious, a natural leader, angry at the "system", can shoot any gun with perfection, solve most all problems with a gun or a fist fight, never show any type of remorse or trauma from their violent "solutions", muscular, always get the girl, only drink brown liquors or beer, never bend, never negotiate, always win, and can walk away from an explosion without flinching.
This shit has been around since the 1940's and it still in use today. It used to be the Lone Ranger, Superman, batman. Then it was the strong independent cowboy taking on the "savages", The 70's it was Charles Bronson and Clint Eastwood taking on the Gangs of the inner cities. The 80's and 90's were Rambo and terminator, the 2000's with Mission Impossible, Jason Borne, John Wick. And James Bond all through out. Just to name a few
Not to take away from the entertainment of these movies and characters but I see lot's of men that take these fictional characters and try to make it their personality. But reality doesn't work that way. They can't go shoot your problems away. Hot women just don't fall leg spread for these guys (which makes them angrier). AND some men don't want to be this unrealistic version of an American man. Which for some reason pisses off those men that do want it....