Have you ever seen people do virtue signaling before?

I can't say who comes up with them, but I can tell you why: they're merely rhetorical devices intended to belittle or denigrate acts or attitudes of which others disapprove, but against which they can make no cogent arguments. In that way, they serve as discussion-enders. 

For instance: someone in the neighborhood lets it be known that they'll take neighbors with limited mobility to get vaccinated. The disapproving user then scoffs, "Oh, he's just virtue-signaling." It works the same way with other "stupid buzz words" or phrases commonly employed by those at the rightward end of the political spectrum. Examples:

Cancel Culture - Ordinary public disapproval of anyone expressing an unpopular or distasteful viewpoint is dismissed as "cancel culture."
The Race Card - If you mention, perhaps, that people of color are disproportionately targeted by law enforcement, you'll be accused of "playing the race card."
Identity Politics - Acts or expressions encouraging cultural diversity in elected or appointed office will be characterized as "engaging in identity politics."
SJW - Those advocating for, say, the poor or any other socially disadvantaged groups will be minimized by those who don't care about them as "social justice warriors."
Crisis Actors - Meant to imply that anyone connected to a tragic event about which they speak is a phony: "These so-called parents of school shooting victims are just crisis actors."
Critical Race Theory - Attempts to educate about historical injustices suffered by racial minorities will be attacked as "teaching critical race theory."
Haters - This one's nearly all-purpose, and can apply to those criticizing anyone from neo-Nazis to entire political parties. "When are you haters gonna stop picking on us?"
Political Correctness - Perhaps the granddaddy of them all, this has pretty much lost all meaning, serving as a catch-all for attitudes making some people uncomfortable: "I'm sick of all this PC crap."

There are others, such as "the blame game" or "victimhood" and, in each case, they're employed to render further discussion futile. Just toss whichever of these applies into a conversation that pushes a discomfort button, and you feel you're off the hook from confronting in any substantive way whatever issue is involved.