What happens to a community when a rabbi leaves

Over the Jewish holidays I noticed that in the town where I grew up there’s a new phenomenon rearing it’s head. Where before a family would belong to only one synagogue, now it’s become fashionable to be a part of many. It’s a shift that maybe is only happening in my town, but an interesting one.
Growing up there was only one synagogue that my family and all family friends went to. This was where I went to Hebrew and Sunday school and met most of my Jewish friends in the neighborhood. Why my parents picked our synagogue had everything to do with my grandparents and because of tradition/community, leaving our synagogue wasn’t an option. While my immediate family has stayed put, because of tradition, the other parts of my family and family friends have left.
Why have they left? Well, it maybe could be summed up as the following. Originally our synagogue was Orthodox; however, our rabbi didn’t believe in separating men and women. So when our rabbi left for another synagogue the identity of our temple was up in the air. Either we remained Orthodox, but have a mehitza or go Conservative. This is when members started to leave and join other congregations.
Our rabbi led the congregation from 1982-2000 and since his retirement our congregation has never been the same. We went through many different rabbis before finally choosing one, but still, our identity as a synagogue has yet to be cemented. Because of this, yes, it makes sense that families might seek other congregations that are more clearly defined, but why do they need two?
I don’t remember my grandparents questioning their Jewish identity. To me it seemed they were staunch in their beliefs and that to sit and wonder, “What kind of Jew am I?” was a waste of time. For them what it meant to be Jewish was already clearly defined. But now being Jewish does not necessarily go hand-in-hand with being religious, as there are lots of ways people connect to their Judaism.
If your religious views are in tact and they match up with those of your synagogue, well, then, there’s no need to go searching for something else. But for those who don’t associate all facets of their Jewish identity to religion how then do they find the perfect fit. Yes, I know we have different categories to choose from, but maybe someone doesn’t fit into any of those groupings explicitly, but is some of each.
Is this why people are members of more than one synagogue? Is it possible that if one isn’t sure of what his/her identity is as a Jew, then one synagogue isn’t enough?