A diagnosis doesn't magically turn a switch on, if a person is autistic, they have been all their lives, even if they never get diagnosed. What is this invalidating bullshit?
You're correct, but so is the comment you're replying to. Lack of a professional diagnosis does not make an autistic person neurotypical, but a self-diagnosis is not the same as a professional assessment.
People are absolutely horrid at objective self-evaluation. Even if someone's making a sincere, good-faith effort to describe a set of problems they're having (i.e., not to impress TikTok) and they arrive at "I'm autistic", there are so many overlaps between disorders. Sure, you may have a lot of conditions that overlap autism, but are you sure the core reason is that you're autistic and not that you have avoidant personality disorder, or OCD, or reactive attachment disorder, or social communication disorder, or sensory processing issues, or even lead poisoning, or sociopathy, or a learning disorder, or...?
It is correct to make a distinction between "I believe I'm autistic" and "I am autistic". Self-diagnosis is potentially harmful in many ways, not the least of which being that the self-diagnosed person may have a different and treatable condition that goes untreated because of their self-diagnosis.
As someone who worked with the community, there's nothing more annoying than people who are just a little quirky claiming they have some diagnosis.
Usually because they just want an excuse to not fit in.
Social skills are skills.
Very few people are just naturally good at it, most people have to work hard at it. And few groups work harder than people who are actually diagnosed.
It's just a lot of lazy people "diagnose themselves" and want to treat it as a get out of jail card for never working on their social skills. They want as much credit for their no effort result as people who have spent decades trying to improve their social skills to end up at the same place.
Like, just slapping a "diagnosis" on themselves means they don't have to try anymore. Even if they actually have it, being diagnosed means they'd have to actually do something about it. It's way easier to just claim you have it and not do anything about it.