I contend that in the kind of nonfiction I write, and that other people also pursue, anything is permissible provided the reader knows what you're taking liberties with. ↗
It's difficult to write a book where a character is on virtually every page of the book but you cannot refer to his or her gender. It gets rid of every his, her, she and he. ↗
There was a period of time in America where the advertising world actually went to the housewives of America and had them write jingles that would appeal to them. It was actually brilliant marketing. ↗