You are correct in saying there is bitterness in some of the posters here.
A lot of the Nigerians are bitter that jobs that should be indigenous are being given to expats, but they also fail to address the actual reason it is happening.
Blaming the expats is easy, because they are an easily identifiable target.
The expats are bent out of shape because by and large, they are treated with disdain by the Nigerians who resent their presence doing "their jobs and chopping their money".
What is the real problem here??
Whatever you choose to answer, the expats are the perceived problem in most cases, not the root of the problem.
The actual issues are almost taboo to discuss, because of the high emotional quotient they generate, but sooner or later, they will need to be addressed.