I have come to realize that people will make changes (including attitude changes) when they are ready to do so, and I don't know that there's anything anyone else can do to speed the process, as much as we love the person and want them to be happy/productive. Although I'm typically in the "stop whining and just DO SOMETHING already" camp, I have been on both sides of this situation a little bit. I'm glad you brought the topic up, though, because I guess I was starting to forget what it feels like and to get a little bit frustrated by people and not remember that I have had bad days or weeks like that too.
Anyway, during some depressed points in my life (I call it being a wad, because I just want to wad myself up on the floor in the corner like a used sock or something), I have found it very difficult to find the motivation to change or do anything. And maybe in a way wallowing in the personal failure can give you this sort of sick pleasure, like when you press on a bruise and it hurts but kind of feels good too... I have definitely felt that way before. Noooooooobody cares about me. I'm such a failure. Booohoohoooo. It can be almost fun. For me though, I really appreciate the "tough love," when someone reminds me that I actually DON'T have any extenuating circumstances, that the roadblocks are all in my head, that I'm being somewhat ridiculous... but perhaps that's because being a wad is not my typical state and that kind of interaction snaps me out of it.
But if a person's default mode or chronic mode is a sort of self-defeating mentality (not that I'd say anyone's default mode is a 'wad' - that's just more of a term I use on myself, when I'm being ridiculous), then I think it will take more than somebody pointing out the "reality" of the situation. Probably the longer you have been in the situation, the more entrenched you become, the more your perceived reality becomes REALITY rather than just a perception. I guess it's kind of like a very big ship trying to change direction rather than a small boat. It just takes a bit longer and more distance.
I actually have felt this way about my mom at times. She has a lot of unhealthy attitudes and behaviors that have accumulated over the years. I love her dearly and don't want to see her almost a slave to those attitudes/behaviors. It would be especially evident to me when I was away at college and would come home and see the contrast after having been gone for months. Anyway, I would try to do things to "fix" the situation for her, to change her attitude or to explain why the way she saw things wasn't true. It seemed like she always had excuses or explanations, typically involving how other people NEED her to be in this role or situation, so she cannot take the steps that would help her to move past where she was in her life. I'm sorry if I'm being particularly vague here. Eventually I realized there was a good chance she would never change and that I could live the rest of my life wishing she were different or else just accept that maybe this was how she wanted* to be, at least for now, on some level, and do my best to be pleasant and helpful anyway.
So but recently - and I have no idea why or what catalyzed it - she has started taking steps on her own, to change her situation and to do all of the things that will help her to be more in control of her situation. It is not linear, and it's very slow, but I feel really proud and I hope she will continue that way. This got really long but I guess it's something I've thought about a lot.
*I do believe people do what they want to do, even if it makes them miserable, like I said earlier, it's a sort of pleasurable miserable