Hetero women read novels about dewy-eyed peasant girls who are kidnapped and made into sex slaves by macho viking beefcakes; it doesn't mean they want to be kidnapped and raped irl.
You need to be able to tell fantasy from reality. And accept that you enjoy things in fantasy that you wouldn't enjoy in reality. Peepz in Japan are very good at doing this; peepz in the West... not so much.
I'll add my two cents. The Yaoi/Slash ML was founded by a lesbian, Jeanne Johnson, and roughly half of its members were lesbians. We're talking about the olden time when there weren't forums like this one and mailing lists were the only way to keep yourself informed and keep in touch with other fans. So yeah, it's not a new thing for non-heterosexual women to have a keen interest in Japanese manga telling stories of love between boys.
Since some find this surprising, I guess I should clarify a few points. First, at the time yuri was not a thing. Second, the authors of yaoi were all women. Third, a helluva lot of yaoi works are considered to be explorations of lesbian feelings and lesbian relationships genderbended as gay boy stories -- yuri in disguise, we would say today. Take at look at this recent manga by Yatosaki Haru to see a good example of the notion.