Below is a short & non-exhaustive list (not ranked in any particular order) of different peoples theories on the true source of feminism, with a short outline of the theory behind it. Some of them are a little more 'out there' than others (if you're polite), or just just 'plain ol' wacko' (if you're not). My inclusion of them doesn't mean that I endorse them, they are only included so that you are aware of them.
[T]he Anglobitch Thesis contends that the brand of feminism that arose in the Anglosphere (the English-speaking world) in the 1960s has an ulterior misandrist (anti-male) agenda quite distinct from its self-proclaimed role as ‘liberator’ of women. This derives from a distinct component in Anglo-Saxon culture, namely Puritanism. This puritanical undercurrent gives women an intrinsic sense of entitlement and privilege as ‘owners’ of sex in a cultural context where sex is a scarce commodity (we call this sense of entitlement ‘The Pedestal Syndrome’). Because of this, the advance of women’s ‘rights’ across the Anglosphere has not been accompanied by a corresponding reduction of their traditional privileges – indeed, those privileges have only broadened in scope and impact, leaving men only with obligations and women aglow with rights plus privileges. This has been accompanied by an obsessive vilification of men in the Anglo-American media, and across the Anglosphere generally.Source: http://anglobitch.com/
Aaron Russo, gave an interview in which he, in part, talked about women’s liberation in the documentary, Reflections and Warnings (Jones, 2009). He befriended Nick Rockefeller of the Rockefeller dynasty, who claims that the Rockefellers help fund the movement. Nick asked Russo what he thought women’s liberation was about. Russo replied that it was about freedom, equality, etc. Nick laughed and called him an idiot. Rockefeller said women’s liberation was about taxing the other 50% of the population. Before this movement, women stayed at home raising the kids. Now women can work, and contribute to the economy.
The Devil/Satan (from the Christian belief system)
Eve was the original feminist who stepped out from under Adam's authority, acted independently and led the whole race into sin and thus the first act in Satan's "feminist" agenda was successful. The key is this, the woman acted independently of her husband's authority and was then deceived - that's what happens as much as some women would like to pretend it doesn't .
If you look at the list of Jewish feminists and see how many of them there are it's not hard to see why Jews (as a group) are identified as promoters of feminism.
Other new members [to the Frankfurt School of Cultural Marxism] included two psychologists, Eric Fromm and Wilhelm Reich, who were noted promoters of feminism and matriarchy, and a young graduate student named Herbert Marcuse.
P.S. I may add more at a later date if I find the time.