To take a special case, the immigrants themselves probably don't feel that way,
Actually they probably do. That's why they immigrated in the first place.
and for some who favour liberal immigration policies the benefit to the immigrants is actually an important part of the point.
Well it's remarkable how strong a correlation there is between one's support for immigration and how strong a bubble one has around oneself to protect oneself from them. Look how many of the most prominent immigration advocates live in gated communities.
That's why they immigrated in the first place.
I can think of reasons why someone might migrate from country A to country B other than preferring country B's people to country A's.
[EDITED to add: Maybe I should give some examples, in case they really aren't obvious. Country B might have: a better political system, less war, more money, better treatment for some group one's part of (women, gay people, intellectuals, Sikhs, ...), less disease, nicer climate, lower taxes, better public services, better jobs, better educational opportunities. Some of those m...
As per a recent comment this thread is meant to voice contrarian opinions, that is anything this community tends not to agree with. Thus I ask you to post your contrarian views and upvote anything you do not agree with based on personal beliefs. Spam and trolling still needs to be downvoted.