From "An Interview with Dr. Philip Jenkins, Distinguished Professor of History (Part 2)" - Ed Stetzer
Ed: There are 34 Western industrialized democracies in the world. And among the majority peoples of those nations, missiologists have not seen a break-out church planting movement. Would you say that is because the way we think and relate to one another or is there something missing that in our context that prevents it from happening?
Dr. Jenkins: If you're in a country where there is basically no Christian presence then something can grow very, very rapidly. But in a country like Britain or Germany, it grows and defines itself up against an existing church establishment. In fact, I would argue that there have been movements like this in Western countries.
I agree with this assessment, it's more difficult to do truly missionary work when you're battling against the established norms of the church at large in society.
This is also why, I believe, a house church model hasn't really picked up steam in the US either. There are just so many "real churches" to belong to.