So, yes, while there are always exceptions, poor families will mostly yield people who will not move away from poverty.
It is as unreasonable to say to those people "move out and get a better job" as to say to a clinically depressed person "oh cheer up, it's all in your head": no, such problems are actually not the problems of attitude and positive thinking, but have external causes and factors (i.e. external to the mind).
One example of such a factor could be poor work habits learned from their parents - but still it's a trait derived from those particular parents. Unless the person sees or learns about "better" work habits somehow, he will in all probability not conclude that is one of his problems all by himself.