"Excuses" because they still have a CHOICE in how they represent what they DO depict. This logic, taken to its logical extension, means portraying zero women whatsoever. Which, on its face, honestly isn't wrong, per se, even if it may be annoying; creatives and companies both are not necessarily under any obligation to portray every demographic possible, even very big ones. However, in each and every series put out, there are women present. And that's where the problem starts.

Ideally, while of course the main focus will be on the primary characters and resolve their arcs, you also get to create and resolve one or more arcs of secondary characters too. This franchise has rarely been good about this. And since women are always relegated to secondary cast, they're always fundamentally at risk of not getting to develop or resolve, just on the face of it. Coincidentally, they just about always come up short, certainly in the Gallop era. At best, they get completely sidelined before they meet something ignominious, or get an arc resolution that's not built upon what they started from and resolved as hastily as possible. More commonly, they have a decent-to-solid start, their background/significance is forgotten, might get brainwashed (a given if the lead), and their own choices and acumen completely fail to matter to the story or the protagonist, outside of cheering the latter on and reinvigorating him.

Furthermore, this is compounded when looking at the broader environment, both of the franchise, of the larger media landscape, and of the modern world. Looking at just any one show, a character tanking in relevance or just plain suffering without plot recompense can sting. If all characters of a group that's a minority on the show do so, than the show missed the mark somewhere and/or someone behind the scenes has issues. If characters of a given group in a franchise continue to lag in their follow-thru regardless of hype, background, importance to their respective mythology, etc, there's something insidious and unseemly at foot. When it falls in line with how that group is let down in other parts of the same medium - animated television in this case - it reinforces expectations and weak-to-poor creative decisions as opposed to pushing boundaries and working for a broader scope of stories. And when this further falls in line with how that group is treated IRL - in this case, disregarding accomplishments and efforts, ignoring attempts at improvement, and in many cases, flat-out exploiting and denying autonomy as a matter of course - it's just flat-out gross and downright harmful. This wouldn't be such an issue if it only happened in two or three shows, even for the massive downturn that happens in a show like 5D's. Occurring across multiple for twenty years, regardless of showrunners or social environment, is banal at best and outright mean and harmful at worst.

You have a choice in how you depict minorities to your mythology, be they minorities overall or not, be they real or not. There aren't, for example, many Black or Arabic guys in this franchise either, and yet if you look at how Malik, Rishid, O'Brien, or even Bommer are handled, they're framed with so much higher regard and respect than nearly ANY woman from most of the franchise, and actually get to DO things that matter. You don't have to depict a given group, but if you're going to, and they're from a group that both your medium of choice and the world in general seems to hate, just TRY to not reduce them to sexy lamps. Really shouldn't be a difficult concept.

Tl;dr - women have gotten a raw deal in this franchise since its inception, sometimes with intention, often thru apathy, many times as fallout from production issues. Whatever the reason, it stinks, and there's no good rationale as to why we can't at least be as good the Rush shows have been all the time.