"Participating in society was identified as the only factor predicting life satisfaction in individuals with ASD [autism spectrum disorder]."
That was the primary finding reported by Lilly Schmidt and colleagues  following their report examining "psychosocial functioning and life satisfaction in adults with autism spectrum disorder" and importantly "identifying areas of functioning that are most predictive for life satisfaction in individuals with ASD."
Based on responses to the World Health Organization Disability Assessment Schedule 2.0 part of the ICF framework I believe (see here), researchers quizzed 43 adults diagnosed with autism "without intellectual impairment" and 44 asymptomatic controls.
"Individuals with ASD reported significant functional impairments and less life satisfaction compared with nonclinical individuals in many areas of life" is perhaps not an unexpected finding in light of what autism can mean to someone and its impact on various areas pertinent to quality of life (see here). That being said: "daily living skills (e.g., getting around, self-care, and household) were not different from nonclinical participants" indicating that certain functional aspects of this cohort at least were intact.
Then back to that headline sentence about societal inclusion and participation being not only an important issue but 'the' most important issue when predicting life satisfaction among participants (this cohort at least) with autism. It's perhaps a sad reflection of today's society that something as simple as enabling a person to become an active member of society is seemingly something that we fail at when it comes to the autism spectrum. I know that 'participating in society' is quite a fluffy term and can cover lots of areas such as employment and friendships through to concepts such as social responsibilities, but surely there must be ways and means that aspects of inclusion can be engineered into plans as and when someone is diagnosed on the autism spectrum?
Aside from big national initiatives to tackle social inclusion and participation, I'd like to think that local communities are perhaps at the coalface when it comes to this issue. Accepting that it might not be everyone's cup of tea, something like local sports and related pursuits could be a good starting point in terms of social participation and how such leisure activities might also reduce some of the health inequalities that are becoming very apparent when autism is mentioned (see here). The paper by Müller and colleagues  mentioned this angle together with various other social supports - "external supports (e.g. activities based on shared interests, highly structured or scripted social activities, and small groups or dyads); communication supports (e.g. alternative modes of communication, explicit communication, and instruction in interpreting and using social cues); and self-initiated strategies for handling social anxiety (e.g. creative/improvisational outlets, physical activity, spiritual practice/organized religion, and time spent alone)" - that may also be worthy of consideration. Potential solutions are seemingly not hard to find.
Music: Kaiser Chiefs - I Predict A Riot.
 Schmidt L. et al. Psychosocial Functioning and Life Satisfaction in Adults With Autism Spectrum Disorder Without Intellectual Impairment. J Clin Psychol. 2015 Sep 25.
 Müller E. et al. Social challenges and supports from the perspective of individuals with Asperger syndrome and other autism spectrum disabilities. Autism. 2008 Mar;12(2):173-90.
Schmidt L, Kirchner J, Strunz S, Broźus J, Ritter K, Roepke S, & Dziobek I (2015). Psychosocial Functioning and Life Satisfaction in Adults With Autism Spectrum Disorder Without Intellectual Impairment. Journal of clinical psychology PMID: 26406481