Yes because there are people of all faiths out there who keep it to themselves. Some would even think that to wear their religions on their sleeves is a vice, like pride. Others would just prefer to keep the world's nose out of their business.
Then you have the showy crowd. I never thought this about Eastern religions until I encountered American Hari Krishnas who are very showy.
It's a good question. Is there some image problem going on, or some underlying doubts, or is this person just not able to relate and socialize on other topics - like me, I'm always drawn to these religion threads. It's such a curiosity to me that people with an interest in science can simultaneously deny science. So maybe some folks express their faith identity out of curiosity too, to provoke a response, to dig into the other person's ideology.
If you wear it like a badge, you probably have an axe to grind.