Do "Neurotypical" people exist? Seems to me like the classic example of how the average woman has 2.5 children, but you can't find anyone who actually gives birth to 2.5 children.

You're confusing avreages with normative pressures. Neurodivergence wouldn't exist if there wasn't some broadly applicable set of behaviors, pathologies, and cultural standards to compare "abnormal" behaviors against. While true that there is no truly normal person, there is a normative standard applied to social groups that is used appropriately and inappropriately. An appropriate use of this norm allows us to identify groups with similar diversions from the "norm" and find ways to either develop treatment for harmful aspects of these diversions or (ideally) adjust aspects of the normative social standard that are needlessly damaging to the out groups. An inappropriate utilization of social norms excludes outgroups and furthers the already existing harm done to those groups (a part of this is the stereotypes that you mention).

Or you could just deny the existence of this cultural technology, call it an abstraction with no use or foundation in reality, and use that denial to invalidate the struggles of marginalized groups because you're so high off your own farts that you'd rather use semantics and "nuance" to be an overly technical weiner and hide your bigotry with a paper thin veneer of "scrutinizing stereotypes".

To throw a personal anecdote in, men generally, and white men in particular, have usually been the ones to inflict their unsolicited "advice" on all sorts of things in my life. Especially things they haven't personally struggled with and don't really understand. Plenty of white men have "the hustle" and "grindset" mentality too. And they're usually the ones to be the most adamant about it.

I feel the commentary on relative privilege here is meaningful. I think bringing up race in the meme can be off putting to some but the overall message of how relative privilege allows one to approach problems with a more hopeful worldview is accurate.

The relative privileges being invoked here being race, gender and financial security, though the messaging would still convey relatable meaning even if they had only chosen one.