I don't know the origin behind it, places just keep bringing it up like it's fact. Bug-catching is a thing Japanese children do, but they don't continue doing that into adulthood, although Tajiri was real obsessed with video games as a teenager which to the American mind means he's autistic because "obsession". People forget childhood experiences
can and often
are used by creators because everyone has unique experiences, so Tajiri's fond memories of bug-catching
is what inspired Pokémon, and probably also led to catch-rates.
View attachment 3048241
Tajiri might not be "neurotypical" for all we know, but he's never gotten a diagnosis especially as a private person so it's mostly just Americans inserting their Western views into Japanese views, as usual. Pokémon being an extremely common interest among autists doesn't help, but given that one study about how a lot of Millennials have an
actual Pokémon database in the visual cortex of their brains, there's a possible link, even though Sonic has slightly closer ties to autism than Pokémon does.