Do you think people can't care about things or have ethical standards without "virtue signaling"? It seems like a lot of people do think so. Or maybe this is a form of "vice signaling"
Sure, they can, but there is a certain subset that does so performatively in nature rather than actually caring about the issues (there are even memes about it [0]), and someone who has to write an entire blog post about why they don't do X is very likely to be in such a subset, otherwise they'd just not do X and carry on with their day, telling no one.