The Gemara itself never included women. It says chayav inash--a man is obligated...
Women drinking is generally discouraged. In Kesubos 65a the Gemara discusses giving a widow wine. Rashi says the reason we do not is that it increases sexual desire. However, if she is used to it, the Gemara says that it doesn't affect her (so we do give her).
This means that an amount not reasonably assumed to affect her is okay, but not more. I think that it is a reasonable assessment that purim drinking exceeds that threshold.
Maybe the Gemara itself never included women. It says chayav inash--a man is obligated... Maybe that's just Purim Torah...maybe not.