Such has been the present interpretation of the course of recorded history. Recorded most often by conquerors, looking favorably upon the the ends of their conquest to justify their means, and if you boil just about every single conquering ideology down for long enough, you will see two things, in this order: greed for what the conquered populace had, and fear of not having enough.
That's not "human nature," that's a response to human nature. Most of us would probably generally prefer to go on living. For many people, that looks like "i just need my necessities covered and I'll figure out the rest." Historically this happened by banding together and looking out for one another, not by hoarding resources and making people do extra work just to fucking exist with a modicum of comfort in a society forever dangling a golden carrot to keep you distracted from the meat grinder.
Trade =/= capitalism. Capitalism is maximum enrichment for a few at the cost of the many. "Capitalizing on an opportunity" doesn't usually seem to get interpreted as "get what I need and hopefully what I want in an exchange that is equitable, just, fair, and negotiable to all parties"; instead, the common meaning seems to be "get all that I can as quick as I can in exchange for the least possible expense on my part", which is not even a full step away from 'The Tragedy of the Commons, ' or, "if there's not enough for everyone to have as much as they want or need, then everyone who takes as much as they need is evil, and if someone is going to be evil AND ALSO have enough than that person is damn well going to be me." THAT'S capitalism.