I probably don't go because of a mix of:
1. Loss of faith in the institutions behind church (for reasons you cite). Similar debate around having a gay bishop in the episcopal church
2. I personally don't hold christian beliefs
3. Local church politics: My family wasn't involved in running the church, so we rarely saw the "politics". But in one local unitarian church I started to go to, the hardcore churchgoers seemed to always have some controversy, usually around left-leaning ideals.
Like many things these days, it's hard to just be casually involved. Those casually involved get turned-off (like the same reason I rarely go on twitter). And the vocal, hardcore folks stay involved, creating various biases towards extremism or a certain point of view.