Okayyy... I'm going to give y'all the benefit of the doubt and assume, for the duration of this post, that you're not just obsessed with hating autistics and that you're genuinely concerned about fairness. Maybe your political opinions include a belief that tax money shouldn't be used to provide services to people who could have avoided the need for the services by making different choices.
If that's the case, then I expect that because you're so fair-minded and so interested in logical consistency, you won't mind my pointing out how such a rule would apply to other groups of people, too.
Let's start with smokers. It's a well-known fact that smoking is a leading cause of preventable disability. Why should society subsidize medical treatments and benefit payments for people who could've just chosen never to light up those cancer sticks in the first place?
And what about the millions of people who have health problems as a result of being overweight? How is it fair that the folks who go to the gym and work out every day are being made to pay higher taxes and insurance premiums because their neighbors are choosing to sit on their butts and drink beer in front of the TV?
While we're on the subject of beer, how about the people who are in poor health because of alcoholism or other forms of substance abuse? They all deserve to be homeless and die on the streets, right?
Let's also disqualify everyone who became disabled as a result of injuries from recreational activities. After all, they didn't have to ride motorcycles, play football, or go skiing, did they? Why should society pay for the consequences of their fun?
Now let's talk about another group of people whose disabilities could have been prevented—men. That's right, men. Statistics show that they have more disabling diseases, more serious accidents, and significantly shorter lives than women. (That's why their insurance rates are so much higher.) All that testosterone sloshing around in their bodies just isn't conducive to a long, productive life. So let's vote all the men off the health care and disability services island unless they make the socially responsible decision to have sex-reassignment surgery. Why should hardworking, taxpaying women be forced to subsidize their selfish choice to keep their testicles?
And while we're talking about personal responsibility, why stop with health care and disability services? We could save a lot more tax money if we didn't condone irresponsible behavior by providing expensive services like public sanitation and food safety inspections. After all, if people washed their hands and cooked their food thoroughly, they wouldn't need to worry about what parasites were in their pork or what toxins were oozing from the local cesspool.
For the same reason, why do we need vaccines... oh, that's right, y'all don't think we do...
Of course, we'd all have to deal with the teeny-weeny inconvenience of going back to a 40-year life expectancy or thereabouts, but at least we wouldn't need to worry about unfairness.