The cause of poverty lies, first and foremost, in our thinking and upbringing. If, as a child, parents form an image of failure, telling the child that he is someone who cannot, that he will never succeed, then what can we expect from such a child when he grows up? Nothing worthwhile.
While on the other hand, that might even spur the child to do more even when the parents didn't believe in him or her. Some children might use that as a means of motivation to get back at the parent for not being in them. However, OP's question about people staying poor could be because there are no means for them to get out of that position. A poor person can only start to change that position if they have the means to start up something that will change that which would normally be financing.
What you say is true, sometimes, it is a powerful catalyst for children to try harder to prove to their parents. I still remember before when I invested in bitcoin, and for a long time, I was almost at a loss and had no profit. My parents always compare me to other peers, it's like they say I'm worthless and parasitic on them. But in the last few years, my investments have started to pay off, and they've started to see me differently.
It can be said that the distrust of parents is sometimes not a bad thing, but on the contrary, it is also a good motivation for us to try harder with our choices.