Funnily enough, that's what Marx was all about too. His approach is characterised as Historical Materialism because it's only concerned with the realities of human nature and things that really happen here, in the material world.
The whole point of Marxism* is to build a political economy that's better/I. than Capitalism. Capitalism is the greatest, most innovative form of political economy devised by mankind but it comes at a terrible price. Marxism is about confronting the reality of the world, which developing a critique of Capitalism in its various forms, and trying to change things for the better.
The only way that struggle can be ultimately resolved is for the working class to gain the consciousness necessary to govern. That change has to come from the bottom up - you can't impose it from above. All attempts to create Socialism from above are doomed to create authoritarian, bureaucratic structures.
Basically, Capitalism as a game is rigged. It rewards making money over performing useful labour (e.g. using knowledge from a medical degree to figure out reasons to refuse insurance payouts rather than using it to treat patients) and results in a world I think most people are clearly unhappy with. The challenge as Socialists is to figure out a better game, a better system of incentives and discouragements to get people doing more useful things.
As to what things are useful, well, that's not a question for one person to answer. It should be decided democratically!
Marx called himself a Humanist. He once said, in reference the the French Marxists with whom he disagreed, "all I know is that I am not a Marxist".