Honestly? It's the same reason that the grandchildren of self made millionaires tend to be spoiled brats.
The first generation is very aware of where they came from, and what they must do to succeed.
The second generation still hears the daily stories from their parents, but are now living in relative luxury and can relax a bit.
The third generation knows no other life, and have no idea of the suffering their ancestors went through to give them what they now take for granted. They hear the stories from their grandparents with skepticism.
TLDR: "Kids these days, they just don't know what they got. Now get off my lawn."
The first generation is very aware of where they came from, and what they must do to succeed.
The second generation still hears the daily stories from their parents, but are now living in relative luxury and can relax a bit.
The third generation knows no other life, and have no idea of the suffering their ancestors went through to give them what they now take for granted. They hear the stories from their grandparents with skepticism.
TLDR: "Kids these days, they just don't know what they got. Now get off my lawn."