For one thing, we’re kinda throwing non-PDA Autistics under the bus here, even if it is unintentional.
Typical autism strategies don’t work for a lot of Autistic people because they’re based on outdated, one-size-fits-all ideas of what Autistic people are like.
For example, some Autistics really do have a high need for predictability and like a consistent routine. "Autism Professionals" have decided this means that it’s best practice to give ALL Autistic children (or adults in care) a strict schedule - and you better stick to it.
However, not all Autistic people actually need or want a completely scheduled day. Even if we do, people often fail to realize that a routine is not necessarily the same thing as a schedule. Also, they rarely consider the fact that we might want a say in what’s put into OUR routine because we might not love everything they choose for us.
This is just one example of a ‘universal autism strategy’ that wouldn’t work for PDAers but also isn’t all that universal.
And then there’s ABA.
If you’ve been in the Autistic community for any amount of time, you know that ABA is not seen as a good thing by pretty much anyone. Unavoidable or the lesser of two evils at times, sure, but not actually good, and certainly not free of harm.
So the implication that it’s fine for "regular Autistics" but not for PDA is just not okay, let alone accurate. It may appear to be effective on some children, but that doesn’t mean it actually works for them.
Also, let’s not forget that internalizing PDAers whose primary stress response is to fawn do exist, and ABA could indeed appear to "work" on them. The constant violations to their autonomy will be silently killing them on the inside, all while their fear response compels them to comply to survive. (This is how it "works" on non-PDAers, too, BTW.)
So while externalizing PDAers will absolutely let you know when something doesn’t work for them with "worsening behaviors," they’re not the only ones who would resist, or should be shielded from, ABA.
I totally get why people say this. I do.
When some person in charge is insisting that ABA and other "traditional" strategies are the only way to turn around your child’s behavior even though you KNOW they would be an absolute disaster, you will say just about anything to get them to back off.
You’re feeling beaten down, alone, and you just want to be understood already. And sometimes the only thing they’ll listen to is something that at least sounds like it still fits within their entrenched belief system. "Hey look, I’m to challenging your entire eXpErTiSe oN AuTiSm, just this one little part over here, see??"
So I get it. Sometimes it gets through when a full on "no thanks, I’m against ABA" doesn’t. We have to be very, very careful with this, though, and at the very least not perpetuate it on social media or in other informal places where no “official” is holding access to proper accommodations and supports hostage.
But even better, push back against these harmful, one-size-fits-all strategies whenever you see them, however you can, on behalf of ALL Autistic people, not just PDAers.