Well, really there are a number of problems with capitalism but the one that frustrates me the most is the insistence on growth as a positive. I am reading Making Globalization Work by Joseph E. Stiglitz right now and he continues on this path. He seems to believe that if we tweak international trade treaties in just the right way then the world will become the happy-go-lucky place the capitalist theorists always seem to predict. Of course, we do not have enough resources for everyone to live like us. I haven't even really seen a decent study done on what level of subsistence the world can reasonably support in a sustainable way.
None of this is the fault of capitalism per se, but it has certainly been embedded into capitalism from its biblical roots. Yes, this like so many other pathologies in the west comes from religious beginnings. Genesis 1:26-30, in which God gives the earth to man and tells him to "Be fruitful, and multiply, and replenish the earth, and subdue it: and have dominion over the fish of the sea, and over the fowl of the air, and over every living thing that moveth upon the earth." Yes, we love more. We love to own and possess and subdue. Capitalism just gives us new reasons and excuses.