As Star has helped me to point out here, I think autism is merely evolution in progress. NTs (not saying this to be offensive) generally have VERY limited theoretical compacity. They rely on labels, trends, group behaviors, to tell them how to act. That generally limits their perceptions, which complicates things.
Intelligence and morality are both a part of evolution, because the goal of evolution is for a species to adopt to it's environment and find happiness. Morality because, if you harm an innocent being, it will retaliate, and that's what we have now with NTs, it's like a chain reaction. So to find happiness we must all learn to get along and live in harmony. This is where the "nice guy" comes in.
Evolution struggles to adopt to the world dominated by the old breed (in this case NTs), thereby finding innovative and more productive ways to get things done (such as when man first made a round wheel), as they outsiders looking in and will learn from the mistakes of the insiders of their day and age (if this is making any since.... I'm struggling with my words trying to explain this so bear with me).
Intelligence means making better decisions, which ultimately leads to better adoptation and happiness.
Now, consider the following factors. NTs are designed genetically to live in a far less modern world, where they were hunters and gatherers, living out of caves. However, we're living in an age where modernization has far surpassed their evolutionary point. A good portion of people working in IT and even the guy who created the net (bill gates) are aspie. Silicon Valley.
We're moving into a computer age now. Everything is being done on computer. Add also that aspies are larger brained than NTs (which has always been the case, the new breed has a larger brain than the old breed). Also consider that much of modern science wouldn't be here if it weren't for 2 aspies, Albert Einstein and Isaac Newton. Plus the ever-rising autistic birth rate. And also being a spectrum disorder support my theory of evolution.