I think that Miller's drama makes specific critiques about the social setting in which it is immersed. One such criticism has to do with "The American Dream." Willy is overcome by the need to "make it" and to "be a success." Miller critiques this basic notion.
Willy's definition of success is the same as the "American Dream." If one has money and wealth, success is demonstrated. Miller is raising question to the idea that material wealth is what determines one's value. For Miller, depicting Willy in this manner is a direct challenge to the capitalist economy that took hold of nearly everything in the 1950s. His social commentary is as much about the people in the society as it is about the messages in that society. Willy's predicament is something that more people undergo and experience if success is defined only in monetary terms. Capitalism's insistence on wealth acquisition as the only metric of success is a defeating one. Willy lives this. In this condition, Miller makes a critique about the nature of reality in which Willy, and most audience members, live.
Another criticism that Miller offers about the notion of success in America as being one so economic has to do with perception. Reisman writes in The Lonely Crowd about how the 1950s marked a shift to "other- directed" from "inner- directed." The notion of the latter is being able to work with an internal sense of understanding about duty and responsibility. The former uses the metric for success as something driven by others and for others' perception. The problem that exists with living a life that is so driven by being "other- directed" is that it is unsatisfying. There will always be someone wealthier, with more power, with a nicer home, and a better job. Capitalism is "other- directed" as an economic system. It knows no boundaries and thus when it sees a frontier that needs to be crossed, it appropriates it and keeps seeking to do so.
There is a perpetual hunger to capitalism, and within this, one finds Willy. Being as "other- directed" as he is, Willy is capitalism incarnate. Devoid of the success, Willy is driven by the need to "make it big" or "be something" and act like he is "somebody." These are Willy's driving forces. Since everything in Willy's life is "other directed" and so much a part of capitalism as an order, he finds himself perpetually unhappy and incapable of being able fully immerse himself in anything outside of money, the trappings of wealth, and what "others would say." It is here in which Miller makes a statement about the economic condition that governs so many Americans, and one that treats Willy in a disastrous manner.