So part of the problem is their alternatives to capitalism. Which are mostly primitivist (as in, destroy infrastructure) communist (in the central planning, grey way depicted in i.e. The Dispossessed) or just kinda goofy. As a lifestyle choice, living off the refuse of a bloated and exorbitant society is actually quite sustainable until you need serious healthcare. As something for everybody to do, a new way of governing, it fails because there will be no society from which to absorb the waste. I think efforts to establish autonomous, non-hierarchal, consensus-based organizations or communities within capitalism is awesome. But ultimately, seven billion people are never going to form some totally sweet Zapatista-style worldwide commune. At that scale, the markets are going to be at work. Capitalism is inevitable.

My perspective is that appropriate solutions to this problem involve taxing externalities (pollution, murderous working conditions that cost society), and reducing the cronyism and corruption that breaks capitalism. Also deciding as a society that we are better off if people are not involuntarily homeless or hungry or dying and agreeing on a social contract to provide welfare.

I want to make the world a better place, so I choose to work on making more, better, cheaper, smarter education available to everyone everywhere. And from society's perspective, this is actually a good investment because it increases human capital and also reduces future costs (as educated folks have fewer kids).

I love communist farms and kibbutzim and I can absolutely imagine living on one and participating in one of those societies. And if you hate capitalism, that's a good way to protect yourself from it. But the farms and kibbutzim themselves are still participants in a larger capitalist system.