If you know someone who thinks everyone is corrupt, or self serving, well... that’s one way people rationalize their own unethical behavior.
The meaner you are, the more assholes you meet.
When someone says “liberals are just virtue signaling” they probably are a horrible person because they don’t believe humans can behave ethically/altruistically.
Or they observe a commonality in human nature, that signaling virtue is a real phenomenon in the competition of a certain species of social apes. And that espousing such views doesnt guarantee their feasibility nor does it mean that the signaler has actually arrived at an ethical understanding of the subject.
EX: Used to be vegan. Saw how monstrous the self-righteous were. Realized that promoting the development of "good", intelligent, ethical, and free people was far more helpful than being an individual in a society of millions of individuals. And maybe a society of such people would be far more conscientious, especially in regards to the treatment of animals, than what we have now.
Also that psychopathic/sociopathic actors could negate my puny individual protest and competing for social rank over them would probably be more helpful than being an "individual" in the liberal sense
When you think of the entire chain of supply and logistics involved in running the modern world, you are inexorably meshed with the world of evil and the "impure". As I said, it does far more good for ethical entities to take rein of this thrashing beast than to posture purity. You might even have to be cunning, brutal, and cold to ward off those who simply don't give a damn. Especially the psychopathic and sociopathic agents.
The world doesn't exist to provide a nice solution set where you can have the conveniences of modern living without the massive externalities of war (to secure and maintain logistical routes) and pollution. To be quite honest, I think the world is inherently a tragedy to those who seek to do only "good".
Helping potential moral agents, aka your "neighbors" (physical or spiritual), with better leverage in the social ape rat race has more impact. You strive to throw off the worse leaders of men and install the better leaders of men.
I was going to go on but forgive me for balking out of a lengthy explanation that isn't structured yet. It's been a while since someone has challenged my stance like that and my intuitons need more editing, so to speak.
So it seems to me you are projecting after all. There's nothing wrong with 'virtue signalling' whether we do it by nature or not. It's ALWAYS brought up in the context of trying to shame white men for being supportive towards women and minorities.
Pot meet kettle.