Anger versus leniency and hatred versus love are two of our basic emotions. They are involved in the management of dangers from enemies (or the opposite with allies). However, like our other basic emotions, they are wrongly shaped in many ways.
One common non-optimization is when the hatred is not attached to people and animals that are endangering our well-being, and more so when it is attached to those who are not endangering us or who are even benefactors. Anger, which usually has a shorter life span, is often wrongly directed to objects that frustrate our will and well-being but there is no reason to recruit the anger mechanism to treat them. A cry of pain from a child in the middle of the night is not supposed to arouse anger to recruit energies, but leniency and caring. A stone we stumble on during a stroll in nature is not supposed to arouse anger too....
Rebels who act against the capitalist system have basic emotions too. Much of what they see and experience frustrates them, and arouses their anger and even hatred. However, The inborn and childhood repertoire of responses to hatred-and anger-arousing objects and activities are usually not the best of steps of grown-ups.
When people who despise aspects of the capitalist system have pent-up anger and hatred, they may be aroused and motivated to do things that may satisfy urges related to hatred and anger, though they are not the optimal ones or are even deleterious to the real solution.
For instance, bombing or setting fire to people or sites that symbolize or even serve the despised capitalist system and specific aspects of it. However, most of the time these acts, instead of weakening the capitalist system, arouse fear (or even anger and hatred towards rebellion and rebels in the general population), decrease the general level of rebellion of the population, and strengthen the capitalist system.
The anger and hatred in the more stable rebels are aroused too, but they do not remain at a chronically high level, they do not overtake the whole being of the person, and do not freeze the more sophisticated cognitive processes that can find the best response and the wisest steps to take in order to bring the end to the capitalist system.
The insurrectionists of the various trends, are at least partially blinded by the hatred and anger aroused in them by the capitalist system, and they do a lot of less-than-intelligent things to satisfy the urges aroused.
Like most other non-adaptive habits people have, the "rationalization" and other processes bring force lot of claims justifying the much less than optimum insurrectional activities they carry or preach to carry.
The complex maladaptive activity of the anger and hatred emotions within social struggle anarchist communists may range for just a short-lived positive feeling on hearing of damage to the capitalist system by any opponent, but one very quickly arrives at the conclusion that it does not advance our cause, it may also find its way to justification or reverence of insurrectionary acts in history by "heroic" comrades, that will not be positively assessed if done at the present.