That's because no one has ever experienced an Autistic-friendly enviroment or had an education based on Autistic strengths(they are still poorly identified when described as calender-calculating and such).
There is something I've learned in my life that some people grasp and others don''t, that is the assumption(and it is an assumption) that Autism causes problems. People point to the lack of problems in non-Autistics as proof of this, but it's a fallacy, an insubstantial case for idiocy to claim greatness. Look at it this way:
To say that Autism is the root of problems even in those described as the most debilitated is akin to saying "the law causes crime because if there were no law nothing would be illegal, ergo no crime" .
When people begin pointing out the common problems associated with Autism(and the big word is 'Associated', which implies a percieved connection not a definitive and unchallengable one) and cite it as an excuse for how Autistics are treated, they are ignoring every common cause: it gives them an excuse not to address the real causes of problems and the needs of people. In the UK we are a bit more progressive on Autism than Canada, the US and other countries because some parents got sick of going to their doctor about their children's co-morbid problems and the reason for getting no help was 'this is common in Autism' .
So they dealt with the problems themselves and noticed huge improvements whilst at the same time recognising that their children were not less Autistic after realising that other children could tell even when there were no evident problems. Autism is far too complex to be viewed in the simplistic realms of Pros and Cons, with the spectrum model acting as a measure of these.