This paragraph from Ashley Fetters’ excellent article for The Atlantic, The Tampon: A History, is revealing,
Tampax arrived on shelves in the mid-1930s—and was one of the great game-changers in 20th-century periods. “For many people, there was a lot of discomfort with the idea of women touching themselves in any way in their vaginal or labia area, especially young girls,” says Sharra Vostral, the author of Under Wraps: A History of Menstrual Hygiene Technology. “A lot of people argued that [tampon use] was not only inappropriate because it might break the hymen, but it might be also pleasurable and might be a way for girls to experience orgasmic pleasure.”