It's not easy for a group of strangers to come together and build trust over time, but that is what needs to happen in order for a Buddhist group to develop. If you're going to practice well, you need to get to know each other and open up to each other. Part of the challenge of making Buddhism work in North America, for converts at least, is to build those bonds.
I'm increasingly convinced that potluck dinners are a good way to do it. Everyone knows how to do it, so there's some kind of comfort level. But you have to share something that you bring, you have to encounter the habits of others and consume them, you have to make some attempt at conversation... all of which brings the defenses down a bit and builds a feeling of community. Even when it goes imperfectly in some respects (you can count on someone to bring an inedible pasta salad).
These little exchanges can become, over time and with some nurturing, the basis for more durable bonds in Dharma practice.
So three cheers for the potluck. That's all.