Conversely, if the world was filled with people with this attitude, humanity would be living in a stable, post-scarcity situation from a very long time ago.

No, because everyone would be waiting around to be helped rather than producing the abundance required for a post-scarcity society (which can never actually exist by the way).

You can't eat or sleep in gratitude, especially from people who have no intent of repaying your favors.

Edit: To be clear, I was talking about the author in my comment above.