Yeah I thought that was weird, along with joining ethnic organizations. I don't really need to explain the religion thing, but ethnic organizations are weird since you are forming an identity based on your unchoosable parent's DNA. I've seen both used by leaders to weaponize their members at their members detriment.
Although, if you are doing politics, I can see this being pragmatically useful.
So in my city there used to be some clubs, like the Ukrainian Lounge, the Polish Club, etc. which was a club where people paid dues and the only real requirement was to be part polish, ukrainian etc. It was basically just a bar to hang out at. The reason I put it there is that those guys seemed to get lifelong companionship and socialization out of it. Instead of shaming people for what may drive them, I am throwing out options I have observed.
Telling people to bond over traits they can't choose seems like an excellent way to isolate people with rare traits they can't choose.
I have more in common with a factory worker in China than I do with the president of my own country, even if we happen to share the same skin tone. I am defined by my experiences, after all, not things like genetics, culture or history.
Although, if you are doing politics, I can see this being pragmatically useful.