I haven't said it in a while so I'm saying it again. I really don't like the attitude that sees a 'switch' as automatically less dominant or less submissive. A switch is someone who is a dom and is a sub. Do you think someone is automatically less good with science because they like math? They're not even entirely distinct skills, experience with one directly makes you better at the other.
Since I can't help myself, and since I find it helps me understand that things, I will now talk about why I think I constantly see this type of thing.
Of course, in part it's because it rhymes with oppositional sexism. "Recreating the gender binary yada yada". I used to find that argument fairly convincing but since studying more feminism I've found it less coherent.
Instead, I think I tend to see it as a natural result of a few competing factors, and the general difficulty inexperienced kinksters have with maintaining kayfabe.
The initial problem is very simple: in transfem spaces, because of compdom, switches will frequently be treated as purely dominant. This is bad. This produces a kind of collective anxiety in such switches that frequently manifests as the "maybe I'm really just a sub" fantasy.
In truth, let's be clear, you are being objectified and mistreated. Compdom is not bad because it forces subjects that shouldn't dom to dom. Domming is not some pedestal, anyone can dom (yes, even you. I've seen toys that are living 24/7 bad ends you wouldn't believe are possible dom effectively and impressively.). Compdom is bad because it is objectifying and denies you part of your desired experience of kink.
The shape of this "switches are really just subs" fantasy at large produces, especially among inexperienced kinksters, the realization that many individuals enjoy being told they're really just subs. This is a fun fantasy, as it satisfyingly deals with a deep anxiety. But, it's a fantasy. It's in kayfabe. Confusing this with reality creates bad outcomes. And, plus, when you apply that to relative strangers, you're kinda doing an unnegotiated scene with them. That's bad.
In aggregate, I see this further builds into a kind of "essential subbiness" belief. I see it most commonly in spaces that are majority identifies-as-submissive. Subs are taught that their subbiness is an essential truth, and taught that their performance of submission is how to attract a dom. This generates a kind of "hierarchy of subbiness" structure, where different subs have relative subbiness. A kind of "who would lose" where both parties are trying to lose. The subbier sub gets to sub and the other has to dom. It's... bad! Lesbian sheep type pattern. So many fundamentally incorrect assumptions that it's hard to even make sense of. All to justify a kind of disavowal of ability or need to self advocate for your own submission.
From this, we get various bad outcomes. from seeing subs that self advocate or break character to express feelings as "less submissive" (from where I'm standing, your ability to self advocate makes you a more experienced sub and therefore better at it). to seeing the erotic d/s relationship between dom and sub as an essential result of a "difference in power levels" in a relationship, rather than like, a negotiated choice. to stuff like seeing switches as less submissive and less dominant because they can do both. It's bad!!!