>You are conflating fitness of the individual with population robustness against systemic shocks

Yes and as per my first example, the ones who don't drink the contaminated water survive. The population robustness is people doing things differently and not dying. Fitness of the individual is population robustness where that individual does something different.

>(1) not everyone understands the basics of evolution, (2) to make my argument I wanted to establish where I am coming from

Right. So did you get past (1) or not? Your argument seems to be that neurodivergents are less likely to pass on their genes. I'm saying that isn't necessarily so.