Regardless of the appropriateness of the comment, there is a substantive dimension to Burt Likko's criticism of a Black Lives Matter speaker's call to "dismantle the system". The question obliquely posed in the post, and discussed at more length in the comments, is whether it is desirable to dismantle the system.
Likko does not give us the context of the speech, so we don't know the speaker's intended meaning. We don't know what system the speaker refers to, and what he means to dismantle it. The phrase might well just be a rhetorical flourish, without specific meaning. But, in keeping with tenor of Likko's post and the subsequent comments, let's take the phrase to mean a radical overthrow of the capitalist system in favor of some variant of socialism. Aislinn Pulley's article, The System That Killed Alton Sterling and Philando Castile Cannot Be Reformed seems to support this interpretation.
I am a communist, and Likko and the majority of commenters at Ordinary Times seem to be sane Republicans, so it's perhaps unsurprising that I favor "dismantling the system" and Likko and his commenters do not. But declaring our preferences, or conducting an abstract normative discussion, misses the main points.
Under what objective circumstances will people actually dismantle the capitalist system? As human beings embedded in the capitalist system that might be dismantled, and who will (if we survive) inherit what follows, how can we think about the question effectively, and, on due consideration, what can we actually do about the issue?
The first question is mostly descriptive, not normative. The capitalist system will be dismantled when and if dismantling the capitalist system is in the interest a sufficiently large number of people, they become aware of this interest, and they have the will to gain the power necessary to dismantle the system.
In this sense, choosing to dismantle or preserve is a pure (as opposed to mixed) chicken game. To simplify for the sake of analysis, we can assume there are two "players": the bourgeoisie and the proletariat (and their respective allies). Because they are the existing ruling class, we say that the bourgeoisie "moves first"; thus their dominant strategy is to preserve the system. The proletariat "moves second", and because the consequences of trying to dismantle the system are worse than preserving it, the proletariat also chooses to preserve.
The goal of the sensible revolutionary is not to try to convince the proletariat to dismantle capitalism anyway and make themselves worse off in the short run; this strategy will never work. Instead, the goal is to change the game so that by dismantling the system the proletariat is better off in the short run.
The goal of the sensible capitalist is to not only preserve capitalism, but to keep the game a chicken game. They must convince the proletariat that they would be worse off by dismantling the system than by preserving it, however much privilege the capitalist class exercises. They have two classes of strategy to do so: increase the reward to the proletariat to preserve the system, or increase the punishment for attempting to dismantle the system.
The best strategy for the revolutionary is to sap the will of the bourgeoisie to impose punishment. The Soviet Union fell precisely when the Soviet Communist Party lost the will to punish the people for dismantling Soviet communism. (As it turned out, quite a lot of people were actually worse off, but thems the breaks. As some wag put it, "Everything the communists told us about communism was a lie; unfortunately, everything they told us about capitalism was the truth.")
Another strategy for the revolutionary is provoke the bourgeoisie into reducing the reward for the proletariat to preserve the system, or goad them into punishing the proletariat even if they preserve the system. This is the strategy that ISIS is using: to provoke western governments into repressing Muslims so severely that they have nothing to lose by dismantling the system, presumably in favor of some sort of Islamic theocracy.
Provocation poses considerable risk: if the proletariat believes that actions of revolutionary justify the consequent punishment by the bourgeoisie, the proletariat believes they have more to lose by dismantling the system. Hence kidnappings, bombings, and other acts of "terrorism" are so counter-productive for a communist revolutionary as to be dismissed out of hand. State repression against this kind of "terrorism" will be seen by the proletariat as justified.
Instead, the provocations must be so obviously righteous per se that the bourgeoisie lose credibility by attempting to blame the revolutionaries. The "riots" in Ferguson show the value of this strategy: protesting the actual police murder of a citizen and the state repression of black communities in the area is so obviously righteous that when they violently suppressed theses protests, the bourgeois state lost a lot of credibility by blaming the violent suppression on the organizers and victims.
All of these theoretical and descriptive considerations aside, it is actual human beings who act in political conflict, and human beings act in no small part according to moral reasoning.
The key moral question is not whether capitalism is better than socialism. For some people, capitalism is better; for others socialism would be better.
The real moral questions, the questions that each individual must ask him- or herself, are these: What am I willing to do to preserve or dismantle the system? What am I willing to suborn, to tolerate, to rationalize? Are there tactics that even if I have good reason to believe would be effective I still would not use or tolerate?
These question are made more complex because we must also contemplate them in light of the answers my opponents would give. We can see that the bourgeoisie and their allies are willing to use and tolerate assassination, murder, rape, torture, mass incarceration, the mass slaughter of civilians in war, the systematic repression of black communities, etc. ad nauseam, and they use and tolerate these means under the mantle of their own authority and thus bear full moral responsibility.
These questions cannot be answered out loud; more precisely, no one should ever trust someone's public answer. I pose them only for my own and my readers' private reflection.
As a revolutionary, I must consider my own actions in light of these answers the bourgeoisie has made manifest.
It is of course possible and not unreasonable to support the capitalist system while opposing these acts, calling them evil (a label I definitely endorse). By all means, work against the evils while supporting the system. But I recommend a sense of urgency: the longer these evils persist, the more the exhortations to work within the system ring hollow and shrill.