In my capacity as a program coordinator for the students of the RIETS Israel Kollel, I had the pleasure of participating in an international rabbinic conference in Jerusalem sponsored by Tzohar, a "moderate" rabbinic group here in Israel. I was only able to participate for the first day, but it was an inspiring, lively exchange of ideas between rabbis from literally across the globe. The sessions focused greatly on exchanging ideas and information, and sharing challenging that span the world.
In one smaller breakout session, we were encouraged to share rabbinic dilemmas. One rabbi shared a powerful issue that resonated strongly with me. He wondered whether his shul is too big. I think that it probably is.
His shul, boasts 400 families (fyi - any information is doctored so as not to identify the rabbi). According to the rabbi, it's impossible to have a relationship with all 400, especially since many of them - more than half probably - don't come to shul on a regular basis. Moreover, there are really only about 50 families truly interested in spiritual growth. The rest of them want the membership services that the shul offers, but aren't really looking to the shul to propel them to improve or change in any meaningful way.
I would add that the 350 families who are complacent actually drive away the dedicated 5o families. These families come to shul looking for a religious experience, and find themselves confronted by people who'd rather talk during davening, leave for the kiddush club, and generally ruin any semblance of a spiritual atmosphere. So they leave, opting to pray in the smaller shtiebel down the block, where they can daven with people who are most "like them," and who will help them create the environment they want for themselves and their children.
This leaves the rabbi only increasingly frustrated, as he watches his best, most committed members abandon ship, leaving him with few devoted members capable of influencing the broader community.
The obvious problem? You can't live on a shul of fifty members. You need the other 350 to pay your salary, and provide the means for the rabbi to do his work.
I've been confronted by this problem personally in Yad Binyamin. Since we moved, we've been davening at the very large shul literally up the street from my house called Beit Knesset Mercazi. I even got myself elected to the board. I like the people in the shul very much - they're great, wonderful people. But the davening leaves a lot to be desired.
For whatever reason, many people in Israel feel quite comfortable bringing their kids to shul, even on Shabbat morning, and especially at other times. I'm also not talking about older kids. I'm talking about babies, in diapers. Often in strollers. Kids run around, all the time, wild, without any supervision. And, truth be told, I have found that many of my fellow-daveners prefer reading Shabbat Alonim (weekly parshah sheets of every shape and color) to actually davening. (That wouldn't be so bad if they weren't really just looking at the ads.) Before I moved to Israel my job determined where I davened. Now, with the freedom to pray where I'd like, I find myself increasingly drawn towards a more "seasoned" shul, where the davening is simply that - davening. (I don't think that the determining factor is the shul's size, but it does make a difference.) Ironically, I don't think that I'm alone. A large number of people have been fleeing the main minyan, resulting in the interesting phenomenon that the 7:15am hashkamah minyan is now packed; the 9:00am "youth" minyan is also full, but the main shul, where every seat is accounted for on a chart on the wall, is empty. Sounds eerily American. I know a lot of shuls like that.
Maybe you cannot really fulfill the needs of a large group of people in one shul. For years rabbis have been complaining about the shtiebelization of America: how droves of members have been fleeing the larger shuls for more intimate davening experiences. Who complained? I did, as did my colleagues. Of course we complained. We had a vested interest. After all, what about ברב עם הדרת מלך - the greater the size, the greater the glory of the King? (Mishlei 14:28) The answer might lie in the previous verse: יראת ה' מקור חיים - "the fear of God is the source of life." Without yirat hashem, all the numbers in the world won't bring the King any glory.