I would think that people who take great effort to go abroad to improve themselves have a higher moral standards on average.
Everyone succumbs to temptation in one way or another. The key here is that while it's OK for a returnee to do so like the natives, it's up to the individual to determine if they want to compromise themselves in such an undignified way.
We shouldn't create a false impression that everybody in China is doing this without discretion.
Seasoned wrong doers can get away with their wrongdoings hundreds of times before they got caught up in the upshot of their wrongdoings. A novice trying to mimic what seems to be the easiest act will get caught the first time he tries to do it.
So, it's rather a logistical problem than a moral one.
