A long time ago I was in a discussion group at an anarchist conference (yes, anarchists hold conferences). At this point I can't remember what the discussion topic was, but for some reason I was prompted to state that I was a materialist.
A young (younger than I was) female anarchist spoke up next. She attacked materialism. She could not believe an anarchist would be a greedy materialist. The whole problem with the world was that people were not idealistic enough.
It was my fault. I had forgotten the vast difference between intellectual, academic speak and ordinary person speak. Because our time was almost up, and others were in line to speak, I did not get to make a clarification.
Idealism, in ordinary language, is acting according to one's ideals. This is generally believed to be a good thing, although people argue about what ideals should be upheld. Philosophic idealism (see also idealism at Wikipedia) has to do with the nature of reality. In simple terms it posits that reality is shaped by idea-like substance. There are lots of versions of philosophic idealism, but they don't correlate much with ordinary ideals like honesty, courage, patriotism, public service, or selflessness.
Similarly, philosophic materialism has little in common with street materialism. Philosophic materialism (see also materialism at Wikipedia) posits that reality is made of substances (usually atoms) that, in combinations, give rise to the world that humans experience, and that exists apart from human perceptions. This is your garden variety scientific view. The Universe existed for billions of years before humans started chatting about philosophy and spinning epic poetry. Thought and even consciousness are created from the ordinary substances of the universe. This is not necessarily a simplistic view. In quantum physics, our best guess at how the substances of nature work, we have a very complex system of space, time, energy fields, quantum rules and waves.
Ethical systems are not very closely tied to the idealism or materialism of philosophy. Often philosophic materialists have highly developed ethics. And idealism, all too often, ends up as either a system of rules of faith with horrid implications (killing non-believers is good) or a vapid nothingness because, for example, if the world is an illusion, if it is all in your head, how do you decide questions of ethics?
I think many people have a sort of natural dualism, and that most religions encourage this. In dualistic philosophies there is both material substance and an idealistic component (often called spiritual) identified with mind, souls, and gods. This appeals to our unanalyzed experience because what goes on in the human mind, particularly imagination and consciousness, seems rather divorced from the muddle and muck of the world, including the mortal and disease-prone human body.
You can spend a lot of time reading the writings of philosophers and religious texts; I certainly have. You may get lost in some complex system that appeals to your personality, but probably you will eventually find your way out of the thickets of philosophic argument back to dealing with the world we all live in.
Philosophy was the precursor of science, and what we now call science used to be called natural philosophy, or the philosophy of nature.
In dealing with that part of the world consisting of human society, we develop a system of ethics, whether we call it that or not. Ethics is a big topic in philosophy. I think society could use a lot more discussion of, and analysis of, ethics. Practicing ethical behavior, and setting up social incentives to encourage ethical behavior, are two important goals for the natural liberation movement.
Philosophic materialism, in summary, is not about greed or the desire to own material things. Dualists and philosophic idealists seem just as prone to greed as materialists. But simply concluding that one is a materialist (or realist) does not provide much guidance in our complex world. A philosophy of life, including an ethical system, is still needed.