games have a level of structure that real life is too complex to maintain. they have a form of instant gratification for achieving goals, while reality is more of a "keep doing X and you'll see the results" which is less tangible and harder for ND people to conceptualise and self-motivate with. there's a sense of accomplishment that is validated explicitly in games, whereas real life often requires you to just be proud that you Did The Thing, which isn't intrinsic for a lot of ND people.