Not that I'm capitalism's greatest fan, but this sounds about as clever as, "evolution is impossible because the second law of thermodynamics says chaos always increases, and the sun doesn't exist."
Evolution and the stars reside in a local entropy minimum but they speed up the increase of entropy by converting a lot of energy. So low entropy and the global increase aren't contradicting each other. But yes, I agree equating cancer and capitalism isn't very useful. Especially when the main problem with capitalism is distribution and not scarcity.
I had an argument with someone about the nature of motivation within a capitalist system. Specifically related to people who find their motivations in non-monetary ends such as personal pride, the greater good, morality, etc. He said that those people were rubes, but I countered that surely those people were suckers. We still haven't resolved...