Most of the complaints I've heard about it have nothing much to do with feminism (unless you define that term really broadly). The complaints are (1) that it's really badly written and (2) that it appears to celebrate abuse in the guise of BDSM. (I am told that actual BDSM folks are generally very, very careful about consent, for obvious reasons.)

I am not endorsing either criticism, not least because I haven't read the book. (It seems to me that #2 might be an unfair criticism, on the grounds that FSOG shouldn't be thought of as a book about domination fantasies and how people play them out, but as a domination fantasy itself.) But unless "sexual abuse and rape are bad" has become a specifically feminist (or even faux-feminist) claim now, I don't see that feminism should get either credit or blame for these criticisms.