But most of the criticism is aimed at Hickman because the character you want is not getting the focus you want (which isn't any individual writers responsibility- they can't cater their story to everyone) and not some serious problematic representation for the most part.
It's not coming out of an objective look at this writing, it's all coming from a place of bias.
Deep characterization comes from increased focus. If she's not showing up that much, there isn't a chance to ruin characterization.
There have been no characterization issues the few times she's showed up. The only really bad instance is HOX #4, and even the reaction to that was way overblown IMO.
Who are these other female characters that he disregards? The only people saying he does to any great degree are Jean stans.
When people are complaining that Jean is a Silver Age housewife because she helped set the table in issue one with other characters (and Scott cleaned the dishes), it starts to become a farce.
Mostly in small action heavy cameos, which have all been serviceable. When the "to me my X-Men" moment is picked apart as being terrible, we're getting into "difficult to please" territory.
I already said I didn't love HOX #4, but I also have a reading of that scene that's different than most others in here.
I think there are instances of mistreating female characters and other marginalized groups that deserve to be called out on, within reason.
Beyond thinking the Marvel Girl costume is a really stupid choice (I hope she starts wearing her other outfits more frequently) and wishing she'd get more focus, nothing Jean related seems like a hill worth dying on at the moment. And the real reason is just that she's not the central figure of the books right now and Hickman likes Emma more. Beyond that, I don't think any solid evidence has been offered that Hickman has a well known track record of disregarding female characters. We need some specifics with Storm, Sue and Valeria Richards, Alia Gregor, Mystique, Destiny, Illyana, Monet, Black Swan....
So if the issue is characterization, how is she supposed to get serious characterization if she has limited panel time? And the panel time is mostly plot related or action heavy, which is how Hickman is utilizing most everyone else to begin with.
It strikes me more as fan entitlement than a serious issue for the most part.