To start with, someone arguing in good faith does not open with: "If you read a little slower, and tried a little harder, you might understand what I actually wrote. I'm gonna go ahead and lay it out here, since you seem to be struggling..."
That's a sign of someone lacking a good argument and trying to hide it behind insults. Either the person gets offended and doesn't respond, or they focus on the insult instead of the argument. Either way it's a weak attempt to get them to focus on something other than the actual argument you are making.
Secondly, speaking of Strawmen: you are insisting something cannot work unless 100% of the people are maximally altruistic, which simply isn't true. If you have 100 people, 99 are altruistic and 1 isn't, things will work out just fine. Now, what that minimum percent of autistic people needs to be is up for debate, but it does not need to be 100%. So I agree that not everybody is altruistic, but not everybody to be.
Which brings me to the third point: you going on about your own personal altruism while claiming people aren't altruistic is a bizarre choice, and if you don't see how that undermines your argument I can't help you. My guess is you do see how obviously it undermines your argument and that's why you're trying to hide it under insults. You probably also want to feel like you're very special and nicer than everyone else, but given how rude you present yourself to people who disagree with you this undermines your argument even further.
Most people are not this unnecessarily rude to people who disagree with them. So if even someone like you who is below average on politeness can be altruistic, it would imply people who care enough about others to be civil during a disagreement would be at least as altruistic if not more.
You being altruistic while also being a dick implies the majority of people are altruistic; as the majority of people are not dicks, and even dicks are altruistic.