To be honest I don't think your first point is accurate. People aren't poor, because they spend a lot of money, they are poor because they don't have a lot of money.
To say that you can lift yourself and your family out of poverty by saving money, makes not a lot of sense. And lot's of the items that one would perceive as unnecessary from a financially comfortable position, don't maybe look that way when you're in the situation yourself. Sure, eating beans everyday might save you money, but then you've spent your life eating beans, and in the end that wasn't the deciding factor.
That said, there are many people ( and I agree with you, our society as a whole probably does) who live above their means continually, I just don't think that that's a problem that's confined to poor people. You said
> It's well established that poorer [...] are generally worse at allocating the resources they do have.
Would you mind expanding on that a little, or link me to some material that you've found useful ?