No, I think the argument is that the greed and corruption of people who are not capitalists aren't as important to the outcome of capitalism, because capitalism is a system in which the economy is organized around the interests (including,
inter alia, greed and corruption) of capitalists.
Which is why the socialist critics of the dominant economic system of the developed world of the early-mid 19th Century coined the name "capitalism" for the system they were criticizing.