You can work hard and still lose hope. Just look at the suicide rates in the farming community. You'd be hard pressed to find a group that works harder than that. Hope is a huge factor. Hard work can only do so much if the system is failing and there's no hope.

It depends on the circumstance. I'm also from a poor background in a third world country (so super poor by Western standards), and although I did work both very hard and very smart, if I had not moved to a first world country there's no way I would have achieved much. Sometimes your environment can make it that hopeless, and I've seen it in many of the younger people back in my home country now. They've essentially just "checked out" of society, which leads to higher crime and unemployment overall.

That's great for you, but go tell that to someone who's lost all hope. If there's no hope then there's little incentive to work hard.

I bet you had hope that your fighting would be worth it. What the GP is saying that if you don’t have hope then you have no incentive to work hard, because the lack of hope literally means that you don’t believe there’s a realistic chance it will lead to success. You need that belief to get going and to keep going.

If by hope you mean realizing that chances of success do exist, then you are right.