why should a visitor get preferences over a resident?
How is someone a visitor, if they want to teach and work in that country, perhaps indefinitely?
In a sense I understand your point but what makes someone more or less 'Qualified' is sometimes things like "will stay in China because he or she has a Chinese spouse" and "Wont require as much assistance man hours" and "cant easily quit and fly away because a spouse is involved" and "can't easily be disqualified on visa problems" and "already has medical exam" etc etc.
Now, i get the complaint BUT the complaint could go the other way just as easily - why should a visitor get preferences over a resident? I'm not even saying thats entirely valid but making the point which is - advantages disadvantages and 'qualified' being made on various factors and that includes even personality, character, probability and so on. (whether we like it or not).