MOPS,
Upward football/basketball/soccer, AARP driving courses, blood drives, divorce support groups ... all of those are sponsored by at least one local church in my area and are open to the community. Church membership is not a requirement. I know of dozens of "trunk or treat" events sponsored by churches on Halloween night, and anyone can go. The largest church in our community has a HUGE July 4th celebration that we've attended and aren't members.
While I agree that churches prefer people to become members, but I've never been involved with one that has told me I was supposed to join. Maybe it's a regional thing, or specific to the faith-based tradition practiced? I'm not agreeing or disagreeing, I'm just confused by what you're saying.
every church preschool in this town is run through the church, as a ministry of the specific church. I am not aware of one in my town that rents space from the church (although I have heard of it in other areas).