While I agree with what you say here, I would not take Glenn's questioning of what I would do even if it was family as his advocation of passively supporting pedophilia. There is usually more there than what you read on the surface.
You are right, it isn't a case of supporting pedophilia (which isn't the case in the example given since the girls in question were 15-16, pedophilia is defined as a love of prepubescent children). It was more an issue of the relationship between teacher and student, and ultimately of unconditional love.
Both the US and Korea are Christian countries, and without a doubt our values and our culture are greatly influenced by Christianity, even if we are not practicing Christians. Korea is probably the most Christian nation in Asia, and there are at least a dozen Korean christian churches within a couple miles of my home. To me, Jesus was about unconditional love and non-judgmentality -- turn the other cheek, forgive seven times seventy, he who is without sin casting the first stone, and so forth.
I think this situation is also very common in a lot of schools, perhaps not so much with the head instructor, but rather at the assistant instructor level. So many times when I visit dojang I see that socially awkward assistant instructor whose whole life is that dojang, his only contact with the opposite sex being teenaged students.
And it is not limited to males, but females too. In fact, here, the daughter of a prominent instructor in her late twenties, one of the chief assistants at her father's school, was dating a 13 year male student. It was quite a school scandal. I wouldn't characterize him as an "enabler", but I also don't think he disowned her either. He clearly loved his daughter.