No one is attacking capitalism as being worthless. But neither is it perfect. The ideal system is a synthesis of whatever is possible, the best of each counteracting the worst in the other, changing over time to meet different conditions. And of course, no one is asserting that synthesis itself cannot go wrong or be co-opted by the ambitious or the unscrupulous.

This is so self-evident to reasonable men that opposition to it (from either side!)is clear evidence of a purely emotional attachment based on belief rather than thought, faith rather than reason. In short, that opposition is a religious argument, or more precisely, a fundamentalist religious argument. Libertarians and Marxists may be poles apart ideologically, but emotionally and intellectually they are blood brothers: opposite sides of the same counterfeit coin.

The ideal of politics is to arrive at a mechanism for administering our economy that works as justly and effectively as possible, given that perfection is unattainable but improvement always possible. Granted, the devil is in the details and there will always be controversy and disagreement when honest men hammer out compromises. Even honest men have self-interests which they sincerely but mistakenly believe to be in the interest of everyone else.

Your insistence that there is only one way and that even speculating on modification or compromise is not acceptable suggests that your approach is not one of practicality based on justice but of zealotry based on dogma. So your argument always relies on accusing your opponents of the same single-mindedness and fanaticism for the antithesis of your position that you exhibit for its thesis. Your enemies can't just be questioning things you say, they must be bitterly undermining everything you say. This absolutism is essential because even one concession on your part puts your entire conceptual house of cards at risk. This is why you feel the need to not let one opportunity to refute any whisper even remotely threatening to your fanaticism go unchallenged. You see yourself as a gadfly, but you are nothing but a censor.

Saying that capitalism has flaws that require adjustment is not the same as saying it is fundamentally flawed, on principle, and must be discarded outright. That is the kind of religious zeal one expects from hard core Marxists--and Libertarians.