As someone who probably is Aspie, with a long family history of it (not diagnosed; aversion to doctors is one of our things, lol. But it's likely my nephew will be diagnosed soon), I don't think it's true that most Aspies can't live independently. It just takes a little longer, and takes more effort. Generally, if someone is so badly affected that they can't live independently, they would have been diagnosed with more severe autism. (Side note: Asperger's is no longer a valid diagnosis. It's considered high-functioning autism now.) Someone with Asperger's is capable of being spoiled and entitled, though . But usually when circumstances force the issue, we manage just fine. I suspect your nephew's parents just let him get away with too much because of his special needs and he sees no reason to change now. But I think he'd be OK if he had to take care of himself (I say that just as a general commentary on Aspies, since I don't know him personally).Like most Aspergers people he is extremely intelligent, passed all his classes in a special school with "A's", but he can't function on his own.
I don't know whether to call it a gift or a curse. I wouldn't be me if I were neurotypical. So it's hard to know how to feel about that. I like being me. Some things are harder and some things are easier. Everybody has troubles, are mine worse than others? Not really. Finding the right job can be hard though.