There is a difference between quiletly going to the store and only buying chalav yisroel products, that basically only your family knows about and it, Telling the whole world what a Helig yid you are because Chalav Stam never touched your lips
With exception of Joseph on the CR, I have almost never encountered such a thing.
The closest I’ve seen to that is in kids, particularly those who recently took on chumros their parents didn’t. They usually get over that within a couple of years.