Very true indeed. The different treatment of foreigners and Chinese native staff by employers most certainly causes a high rate of frustration if not jealousy among the Chinese staff even if they don't show it. Foreigner are often too self-centred and only see the problems they have. It therefore would be better to take a broader perspective. Eventually one may arrive at a point where a solution is at hand.

2. To show support towards local staff. A simple example would be - upon hearing a member of the management laying into a local staff member, a foreign teacher would go over to the area where the 'disagreement' was taking place. You wouldn't have to actually interpose in the situation but the presence of a foreign teacher was usually enough to modify the bad behavior of managers towards local staff. In this example you're actually using the unbalanced system to restore some balance and support your colleagues.