[shigawire]

Is your contention that criticism of the capitalist system is best explained by sour grapes?

I think someone strongly anti-capitalist would not be incredibly interested in the best strategies to accumulate wealth. And that is not a point against their critique.

Now if they didn't understand the system they were criticizing that is another thing. But in your comment it seems to imply only the rich would have a valid opinion - though I think that class has obvious biases in this discussion.