To be fair its kind of a two way straight(Edit: street
) these days. And if you want to speak plain then by "male dominated fanbase" they specifically mean white men, who, obviously, are still a majority of folks in the western escapist nerd culture. This culture has realistically been hijacked from the top by toxic people who's penchant for identity politics and "modern audience" rhetoric is what this core fanbase despises, mainly because its proponents despises them in turn for their "hetero-normative" skin colour and sexual orientation.
In that context downright mean and confusing attitudes
like this are pretty common we have seen it for years now and its been normalised across established entertainment, not only star wars, but comic books, TV shows, tabletop games, movies, video games etc. These mediums have essentially been appropriated and are collapsing before our eyes, and if not collapsing have been robbed of what made them appealing escapism in the first place. Sales etc are awful, reactions to new stuff is terrible and mocked relentlessly etc. It's pretty bad, and a few youtubers are making videos profiting off of it, which upsets some people who want them to be wrong.
In terms of Star wars, that's exactly how you get "the force is female" on the one hand (said in front of an audience which will have almost certainly been 95%+ male) all the way to "star wars is failing, and its because its fans are sexist and racist". If they didn't have that divisive shit and yes, focused on quality actors/writing etc we wouldn't be in this position, but its also about "the message" as one particular youtuber likes to put it, and generally this message is disliked for both its malicious implications and it taking precedence over pretty much anything else.
Yes some of the most successful shit of all time had these none standard roles, clearly this isn't the only reason its the mountain of baggage that comes with inherently forcing it, aye like directors virtue signalling and/or berating people about something which should be inconsequential, often before something has even come out.
Sarah Connor and Ripley are definitely good examples of the differences between old and modern writing, as they were very specifically written to be actual women, they were badass yes but that was manifested very much through motherhood and tenderness, they were also allowed to show weakness and femininity etc. Disney Star wars is the complete opposite, they are generally perfect with strong masculine traits, often but not always with the added bonus of hot takes about how unnecessary men are, where its like these writers can't help but tear us down at the same time rather than sharing a screen presence like Sarah would with Kyle or Ripley would with Hicks.