Do you literally mean as a mob? If anything, it's the exact opposite from I have known.
Anyway, organized religion can be good since it's, well, organized. Sure, some people may believe in the same deity, but they might not grow in their spiritual faith if they solely prayed alone. While in what you call a group, people can discover more about their faith through the experience of others. Besides, the world wouldn't even be able to function if everyone stayed "in a closet," so why can't religion be organized like everything else?