So what you are basically saying is that Christians won't drop it till everyone on the plant is a Christian? Is that the argument you are setting up?
What part of 'Go forth and teach all nations' do you not understand?
Yes. But I'm not setting it up, they are. There are, of course, some Christian groups which do not evangelize or some which stress it more than others but missionary work is an essential part of the Christian faith. Those, such as the teacher in this article, who try to separate Christians from Christian missionary work are telling Christians not to practice a basic part of their faith.
We all know what the real case is: This teacher doesn't want Christians doing what Christians do. Fine and good. But at least she could be honest about it.