i rlly does feel like the latest version of this labels discourse is a few loud people who dont want to share a label for w/e reason and are working backwards from there to exclude anyone they dont like or cant understand
I'd say you're close, but I think it's a little more complicated than that, and I have a good idea about what that "reason" is. It starts with a p and ends with an a, but before you guess, I think I should tell you how I've seen this mess evolve into what it is today.
So, at the start, there was a good cause with a good reason behind it. Non-verbal people have spent a long time being spoken over by other people who have misused their label to refer to temporary speech loss, instead of a long-lasting condition. This made it hard for non-verbal people to find each other or speak about their issues. Eventually, the issue started gaining attention, and so there was a boom in people trying to tackle the issue, such as those who gave out reminders that non-verbality was a "permanent condition".
Which was fine (good even) until they started doing the same thing to semi-verbality. Because semi-verbality covers a lot more ground, including fluctuating and fluid troubles with speech, as I mentioned in that post, and "permanent condition" could lead – and has led – people to think that you're only really semi-verbal if your speech difficulties are exactly the same all the time in all circumstances forever, due to people's associations with the word "permanent". So, semi-verbal people saw that and went, "Wait, these word choices might give people the wrong impression."
"It'll be fine!" said these people, who on the side were actively erasing parts of our communities, like any allistic people who were semi-verbal or non-verbal, and saying selectively mute people + people with a fluctuating speech/language ability were not actually semi-verbal. "We're doing this to help you!"
note: The semi-verbal community didn't really ask for this help, nor were we consulted before people started talking about us. Remember, that was the non-verbal community, who were sick of people misusing their terminology, and wanted people to fix their shit. People just saw that our labels looked similar and assumed our communities were basically the same with easily ignorable differences; they didn't see the need to learn our history or experiences as semi-verbal people when they had this other community to listen to. So, people went from erasing the meaning of non-verbality and speaking over non-verbal folks... To erasing the meaning of semi-verbality and speaking over semi-verbal folks. Great job, everyone /(sarcasm). Don't know what I expected. Performative support at its finest.
This is where I'd say the system exclusionists (as in, those who try to gatekeep this terminology from systems) come in. Everyone likes to say they accept systems, but nobody seems to have realized that involves deconstructing their biases against us, like how they don't actually see alters as individuals worth respecting and instead as Sparkly Imaginary Friends (who it's totally okay to dehumanize, don't worry, all the cool kids do it). Because they don't actually see us as individuals, they don't see systems as "one individual is non-verbal, this other is fully verbal, both share a body but are distinct and different from one another, and so they need different language to describe themselves". No, they see us as interchangeable, able to be judged by whoever in the system has it The Best (sometimes even making up an alter if none of us fit their standards or whatever the fuck) – which means we're basically the same as those who were misusing "non-verbal" to describe temporary speech loss, tbc, that's their logic – and so they chose to do so, acting like we are just Privileged People Trying to Act Special and Steal Words (hello again, pluralmisia that no one has actually challenged even though they totally support systems). This is despite the fact that even psychologists and doctors, who can't seem to go two sentences into talking about systems without dehumanizing our alters, will describe individual alters as non-verbal or semi-verbal, and have done so for decades.
And because people now completely misunderstand semi-verbality, dunking our history and community into the trash so they can give us almost the exact same definition as non-verbality with a few words changed, people have conveniently made it so that the systems they've harassed and shamed out of using this terminology on an individual basis also aren't "allowed" to call themselves collectively semi-verbal to account for the differences in speaking ability across their system. Because that might imply that semi-verbality really does include all those people they pushed out not five minutes ago, and they can't have that!
Pluralphobes perpetuate this bullshit, so they're absolutely in part to blame for it, but I wouldn't say it completely originated from them. It's more like they're taking advantage of it to erase us. They didn't need to work backwards – the people who didn't want or care enough to consult semi-verbal people before speaking about us, as well as pluralmisia as a whole, laid the groundwork for them.
To end on a positive note: I don't see this bullshit sticking around forever. Plural education and activism is slowly getting its gears going, so I think even the performative asshats will eventually have to get themselves in line as more and more people learn and accept that alters are individuals and systems deserve respect on both a collective and individual basis. As that happens, this strict gatekeeping of semi-verbality will fall apart, and both non-verbal and semi-verbal alters will be able to breathe easier. In the meantime, we've gotta keep trucking, refusing to bend to this bullshit, and reminding others that it is bullshit. It is bullshit born out of hate and intentional ignorance, and we can't forget that.