Jason Helopoulas has an outstanding post on reasons why people should and should not leave a church. I would only add to his list one more reason people have a legitimate reason to leave: "If the minister is unwilling to work hard to feed the sheep with the pure milk and the meat of the word. If the sheep are not being fed through solid, textual, Gospel-centered preaching--and the issue has been addressed to the pastor who is, in turn, unwilling to change--that individual/family should leave. If the leadership fails, the church will suffer greatly. The church is, in many senses, only as healthy as the leadership. You can read Jason's post here.