Clyde, the problem with the argument is that in the end you cannot change the opinions of the people who argue against you. To keep things simple I will use 1 reason for this: The Chinese themselves haven't applied these standards to their own society, and they actively perpetrate immoral behavior everywhere in their own country. At the most recent place where I had worked in China I had heard a case of a gym teachers who molested underage students at one of the primary public schools in the same city. Going after underage students however is old news as going back 4 years ago there was a more famous case that involved government officials, teachers, and other people of social status who participated in a prostitution ring involving middle school age students, specifically virgins which are sought after in more than one of these sick circles of influence. Even on the Chinese discussion forums I have seen written stories about high up military officials who went after underage non-sexually active girls. There has also been cases of corrupt behavior where a government official on a lower rung will give his wife or mistress for a short time to one of his superiors to get more leverage at his job, and even this is old news.

As much as I may not like the age discepancy, the whole argument about dating students is simply not even taken as a priority in ANY way whatsoever because the folks who hold even a little bit of power in china actively benefit. You may not like to hear this but occasionally there will be younger women across all walks of life in china who are raised to believe that using their bodies for social leverage isn't a bad thing, it's necessary. Any of these chinese who reads your posts probably would not care to think too much of your opinion, they would just laugh it off. As for the local chinese most of them would think they already know where the issue of good/bad lay, and they don't need to hear the opinions of an expat.

We cannot change people or how they think, soemtimes when you look a little deeper you realize that they very folks whom you feel a responsiblity for defending are the ones who don't care at all about standing up to the injustices in their own society. You are not in China anyway, why care about what people (foreign or local) think? Let their own actions determine their fates.