People are products of their environment:

The ratio of people that actually utilize available advancement services is smaller in a low income area.

In some cases ambition is hard to have when your peers (family and friends) lack that valuable attribute.

Think about high income families: the ratio of people who actually help low income families is actually smaller that the ratio of high income families who help themselves.

Not saying what's right and whats wrong just giving an example to show how people can get consumed in their environment.