Interesting read.
I think it's quite easy to read Wolff alluding to something akin to the 'toxic masculinity' that ejp626 mentions here (apologies for the font size, posting from my phone)
"In his later work, especially in the novels, we can see Hemingway the writer sometimes yielding to the persona he developed, the persona we boys aspired to: tough, taciturn, knowing, self-sufficient, superior. This could bleed into the work, painting his leading men in caricature."