Most people don't get that its a developmental delay. Its true that with lots of work and support they can overcome many of their difficulties and go on to achieve great things. Unfortunately, it isn't just the social/communication stuff, its very often the comorbids, such as processing delay, auditory processing problems, gross and fine motor problems and sensory issues etc that make it so much harder for them to live a 'normal' life. (Whatever normal is.)
When you have a child like mine, whose core strength is so low that he actually finds it painful to sit at a desk, you start to see how difficult it is for a lot of these kids to even begin to achieve academically.
Some of that's why I would call into question the validity of tests such as the WISC, as if he undertakes a test whilst attempting to sit still at a desk, whilst struggling to focus and track visually and experiencing all manor of sensory distractions, it can't really be a true indicator of his actual intelligence.
It would be very interesting to know how TG would have performed in a similar test at the same age.