I think it has to do with unkept promises and learning to pin your hopes on one solution. With my AF, I felt like he held the promise of everything getting better. After all, he sure didn't model empowerment and changing things for yourself. Like him, I had the false belief that change came from somewhere outside.
Quite frankly, I think the religious approach has a lot to do with this. AF believed god had set him aside for some grand purpose - although he didn't know what. So it made sense in his mind that he just needed to sit back and not do anything until that purpose was somehow realized. Until then, he was helpless to do anything. He'd be happy to tell you about it anytime, especially after a few.
End point: I think we're trained to deposit our hopes in one place and wait for that return. Like GiveLove says, this may come in different forms (family relationship, romantic relationship, etc) but the formula is still the same.