Do and Allow
The Counterrevolutionary says that the fundamental error underlying leftism is its belief that "if you claim that your cause is humane then all your arguments and subsequent actions are excusable." This is quite a Kekesian diagnosis. (See my series of posts on Kekes below.) For Kekes, as for CR, people should be judged on the extent to which they are disposed to cause evil, not on whether they "meant well".
I add that there is another fundamental error: the erasure of the do-allow distinction. This is the deeply held value that doing harm is morally worse than allowing it. (E.g., not putting the neighbor's kids through college is not morally equivalent to actively depriving them of a college education; does the denial of this distinction ring a bell?) The distinction is one that we cherish and live by. The threat from leftism is one of violence. The distinction is part of what makes life worth living for us; it represents liberty, the right to live unbeholden to the desires of others. Since there is no argument against the distinction, the stance of leftism is simply in basic opposition to us. There is nothing left for it to do but violence to us, in order to bring about the desired "progress". We won't part with fundamental values without a fight to the death.
The leftist erasure of the distinction flows from facts such as these: The rich allow the poor to be poor. People maintaining traditional Western values allow allow alternative lifestyles to go unappreciated, uncelebrated. Israel allows Palestinians to suffer. The happy and fulfilled allow the unhappy to remain unhappy, and they do this happily. These facts drive the leftist to shrieks of outrage.
The leftist disguises envy and hatred as moral indignance. The unhappiness in the world can be eliminated if only the well-off would fulfill their duty and stop allowing the harms. Their allowing the harms is supposed to be morally equivalent to actually doing evil.
But we will not part with the do-allow distinction. In addition to the fact that we cherish the value and have been given no reason to relinquish it, there is another reason not to relinquish it. Doing away with it puts the good at the mercy of the wicked. People have a tendency to be lazy and wicked. The wicked and lazy may take what the good have procured, if do-allow is done away with. The good may not defend themselves against this attack if do-allow is done away with. The result is any one of the hell-holes known as communist states. Murder to get there, misery after you arrive. Liberty rights are not merely self-interested. They protect us all from evil, human nature being what it is.
CR may be right that it is time to stop playing the game of debating with leftists. There is no rational debate here. It's simply a cultural war. Many millions have died already.
UPDATE: The do-allow distinction should not be confused with the position that no one has a duty to help others (i.e., the position that it is never wrong to allow harm). It may be gravely wrong, even punishable, to allow someone to die. This does not entail that allowing harm is morally equivalent to doing harm.