While I think you're correct the authors opinions do appear to shine through in that last paragraph, it seems that efforts have been made to show this history without framing.
Does the article make the case that an alignment with Satanism is a bad thing? Many modern western values align closely with Satanism. Satanism in its modern form was a deliberate effort by some to oppose Christianaities stronghold on the western world at the time.
Is the opposition to Christianity a problem for modern Feminism? Even an historical opposition?
To me this article simply reads as early feminists rebelled against a society they felt was oppressive to them by adopting what they saw as their enemies enemy as a mascot. I don't think that is particularly disparaging of feminism is it?
Full disclosure, I’m a fundamentalist Christian.