NIMBYism is rationalism. It is irrational to think you can/should have policies in your system to serve people from a separate system. It presumes that you can establish a metric for right and wrong that applies to others, which is really just jingoism.

Edit: wrt your 'A', there is a massive amount of things not said about how immigrants take on the values of their new country. Cato has published a few papers on that and it is always in the context of large aggregate stats dominated by immigrants from similar cultures (some might disagree, but Mexico is VERY similar to the US; Syria not so much)