Well, autism has a tendency to cause problems socially. And, because many people view sex as an intimate social interaction, I think it's not unfair to theorize that people with autism are less likely to have sex. I'm asexual, so I don't even desire sex, and although it's impossible to pinpoint this to autism or something else, it's definitely going to make me have less sex than everyone else, who appear to be sex-crazed.
Of course, having less sex is a good thing. The same amount of land and wealth, with less people to share it with, means that the average person goes up. The amount of STDs spread and unwanted pregnancies created by the craaaazy amount of effort people seem to put into having sex is mind-blowing. We could do without it.
The article does have a few unfortunate implications, including the idea that women don't desire sex.