It sounds as if from your point of view, there are lots of good reasons why he should want to please you. He, meanwhile, doesn't sound like he cares all that much if he pleases you or not, and all the reasons why he should want to seem mostly lost on him.

There might even be a vicious circle going on here. If he already had a self-esteem problem which was made that much worse by his having a history of schizophrenia, he might be seeing your taking care of him as one more reminder that he couldn't make it on his own. Resentment of his own situation might be driving him not to cooperate much with you. Understandably, that would be a problem for you but the more you leaned on him to act differently, the more he'd resent you and dig in his heels.

I don't know what a good solution would be but I'm thinking, find a way to get him out of your space. He might even come to miss you after a while but he can't as long as you're always there to remind him of whatever he's doing wrong.