It’s mostly a large-parish thing. It drives me crazy. I’ve never actually made friends with anyone through church, and friendships are what cement a community.
John Taylor Gatto, who writes mostly about education, distinguished between networks and communities. Networks aren’t bad in and of themselves; they help us accomplish important, (and sometimes unimportant) things - coffee hour donuts, pretty altars, Lenten suppers, etc. But if you go into a network looking for a community, you’re going to be heartbroken. In a network, people will never call you for friendship; they’ll call you only when they want something out of you, usually time or money.
Some parishes are starting to improve. Small faith communities are a wonderful idea, as are book groups. In the Anglican Church in which I grew up, the bishop had people sign up for small dinner groups, i.e. inviting each other over for dinner, picnics, BBQs, etc. He knew what he was doing. People stuck around that church because they formed friendships.