This kept coming up in the other thread and I didn't want to drag it off topic so thought I could start it here. I'm genuinely interested as I don't see any connection.
To explain, feminism to me is about equality of treatment (e.g. same wage for same job), equality of opportunities, the rejection of a system in which women are property to be exchanged, shared or abused. But I don't get what it has to do with lifestyle choices like being a SAHM.