Tareg Quillien has an article on virtue signaling up at Aeon.co. It's marginally better than some of the other articles I've seen, but suffers from many of the same problems. Quillien asks:
Why do we scold virtue signallers for having it easy? The urge to dismiss someone’s actions because they took no effort is powerful. But does it not make more sense to focus on what that action actually achieves? Why do we often focus on the costs people pay rather than how effective they are at making the world better?
The answers to these questions are, respectively: People don't scold virtue signalers for having it easy, people scold them for faking by substituting very easy, very showy things for very difficult, less showy ones. No, it does not make more sense to focus on what the action actually achieves; 'virtue signaling' is a moral term in the general family of 'hypocrisy', which is not about what the action actually achieves. We don't focus on the costs people pay, we focus on the fact that they are trying to manipulate people into giving them the extrinsic benefits of doing good deeds without doing good deeds, thus (among many other things) worsening the incentives for actually doing good and therefore making the world worse under the pretense of making it better. One of the things that makes Quillien's article better than most is that he at least recognizes some of this. But then on the basis of some extremely loose analogies, he continues:
So let’s concede that some virtue signalling is fake, but does that mean it is bad? Here it is useful to take a step back from our default mode of thinking. Evolution designed our brain to make us good at small-scale interaction, but we are not very good (or especially concerned) at evaluating the large-scale social effects of things. As such, it is easy for a polemist to throw discredit on someone who virtue-signals by pointing out that there is no guarantee that the person actually shares your moral values. But is this the right yardstick by which to evaluate these signals?
All actual virtue signaling by definition is a kind of fakery, like affectation and posturing; that's the whole point of the term. But the yardstick Quillien is criticizing is simply irrelevant, because it is not the standard people are using. The issue with virtue signaling is not sharing values; it's irrelevant whether the virtue signaler shares the values or not. The issue is shifting reputational benefits for virtue from difficult virtuous actions to easy symbolic gestures. Quillien goes on to argue that virtue signaling has value in solving a moral coordination problem, but this is necessarily backwards. Virtue signaling is not necessary for the common knowledge that coordinates action, but this is quite clearly because it presupposes it; virtue-signals get their force and attraction from the fact that values are already shared within one's group, and it is the force and attraction that tempt people to substitute them for serious work. Contrary to Quillien's claim, it does not create common knowledge about values and norms; it is parasitic on it.
