I think women can find betas attractive, but only if they're like incredibly handsome, high betas or something.

Women were not sexually attracted to betas. Not even when they were marrying them as virgins.

Why else do you think female sexuality used to be considered "rare" and a "mental desease" at one point?

https://www.psychologytoday.com/blog/all-about-sex/201303/hysteria-and-the-strange-history-vibrators

Women were so sexually frustrated, they suffered from "hysteria".

http://asexystuff.blogspot.gr/2008/11/women-arent-asexual.html