It seems to me that the basic error here is assuming that one’s sexual desires somehow reflect on one’s social values, particularly if one has a hidden or obscure kink.
I consider myself lucky to have avoided experiencing this kind of shaming that appears pretty common from M/f and SW fans. It wasn’t until when I was older that I realised that the fantasy could be (mis)interpreted as misogynistic. There is undoubtedly misogynistic material and fans out there, but I don’t think the fantasy itself is inherently so (both sexual and non-sexual content).
I think people grossly misunderstand by essentialising it to “big = dominant, small = submissive” and conveniently omit other elements like agency (a character’s or the fan’s), subject portrayal, audience, perspectives, themes, etc. It’s the same with F/m and GTS which can also get confused: I also think it is not inherently misogynistic and you would think exemplifies a fantasy where women can feel empowered. In reality, that is overwhelmingly not the case within the fandom and its content (even mainstream content tends to leans towards the male gaze) - consider, e.g. the paradox of power.
It’s the epitome of misogyny to dictate what a woman should/shouldn’t like.
☝ simply put.