Doc Brown, the movie's moral center and mentor to Marty, is the proletarian scientist. He invented time travel for the betterment of humanity. He describes profiting off of his creation as a "trivial purpose" and urges Marty not to use the future sports almanac to enrich himself. The only thing he uses time travel for in the movie is to help Marty's future children

Biff, the villain, is the movie's embodiment of capitalism. He did not invent time travel and does not understand it, valuing it only to the extent that he can exploit it for profit. His only assets are his capacities to steal and inflict violence. He exploits what he did not create, stealing the discarded sports almanac to enrich himself. In doing so, he turns Hill Valley into a capitalist hellscape

Marty is the youth, inexperienced and uninitiated but full of potential. As the representation of the future, it is vitally important that Marty take Doc Brown's attitude toward time travel rather than Biff's. His narrative arc is realized when he sees the capitalist outcome (Biff's future) firsthand, and it is ultimately he who must act to ensure it doesn't come to pass

I am only half-joking