Chic, he has a cognitive thought process and can formulate tactics (that you see through). If he has anything, it is a more mild personality disorder, (JMHO). He wants what he wants.
what on EARTH is keeping him from doing fast food, janitorial work, stocking shelves or pumping gas? you don't have to be a rocket scientist, but you can earn a living doing these things and contribute. 8 years of "being bored" is a lot.
I think his biggest issue might be selfishness and laziness. I'm glad that your daughters told him their opinions. it is time for him to grow up.
good grief, my 68 year old brother (who is retired), just got a 25 hour a week job at Costco, pumping gas.....$11.41 an hour. They offered shelf stocking or bakery work, but he thought this would suit him better...shelf stocking starts at 4AM-9AM and he does not know how to bake.