I'm aware that, here in American society, we believe that our framework guarantees the opportunity for attaining these needs. However it does not ensure it.

Ancient western philosophers like Aristotle and Cicero certainly lauded these goals as being an integral component of a well functioning free society. I am also aware that Locke offered a more libertarian philosophy regarding these needs, placing the onus on the individual instead of the society at large. However, Locke's philosophy was extremely ideological and not necessarily realistic. Furthermore, I'm aware of the influence of social Darwinism on western politics. However, I don't understand the extreme divergence in thought.

Many western philosophers throughout history have proposed civic duties as an obligation to the society of which one is a part. Why ignore or discredit their views?

Edit: title should say political philosophy. I wrote this on my phone. Please excuse the typo.