Have you considered part of the discounting may be the confidence with which random people with no medical training want to diagnose someone they’ve never met with a neurological disorder based on seeing them on television?
My wife has MS, that doesn’t mean I can diagnose it.
A diagnosis will tell you what caused the symptoms you saw, and how quickly those symptoms can be expected to progress. But you don't need training to notice the symptoms. We're all supposed to be alert for them in order to help people who may not realize they are in decline.
I mean, you're not wrong. Still, that's what people do, and the perception of that debate did no favors for that very reason.
My mom watched it, and she said it reminded her of her grandmother who she took care of, with dementia. Again, that's not saying it's right to jump to. Just happens.