When I first became an attorney I used to engage in arguments, trying to get people to think for themselves. I thought of it as furthering the education of the populace. Which is good for society. Then I realized that very few people are actually interested in the truth. Few are interested in the process of critical analysis of any topic. They are more interested in a point of view. Humans very much seem to want to be seen as 'right' more than actually being right. So arguments become debates. Petty, unproductive and self serving for both parties.
That's a petty and unproductive generalization.
It is a generalization, but it is a surprisingly accurate depiction of Western culture at the moment. If people had an interest in truth, they would be more willing to abandon ideas or conclusions that are false regardless of how much they like the idea. This is not the way Western society currently functions. There is a greater emphasis on people feeling happy or good about themselves, about their ideas, and thus more of an emphasis on "being right" rather than actually determining whether their point is correct or not. This is also promoted in politics, where the point isn't to do good things but to say things that will get you elected. (Of course I'm generalizing here, based on how prevalent this seems to be at the national level.)
It is also a symptom of the relativity of truth and rejection of the idea that there might be an objective truth to some problem. For example, the statement "well that's your opinion" can be an acknowledgement that my initial intention was for you to agree with me and not for us to reach the truth of the matter. If I was concerned about truth, I would agree or disagree with you based on rational or empirical grounds, not based on how much I like my conclusion or argument. (The "you" in this statement is for the purpose of illustration, it's not directed at anyone in this forum.)
Such a concept is more obvious in fields where there is little argument about objective truth existing (such as the physical sciences). Although we could certainly say there is an objective truth to social problems, it's not easy to see that might be the case or how we could investigate it. Academics have this issue, and they are supposedly trained for this as well as it being their apparent job to investigate such things. Therefore, how can we expect the average person to investigate the truth of social problems, especially when they may be more concerned about having an income than about truth?
Anyway, getting back to the initial issue, I think it comes down to the following. The state of the world is such that the people in it, and the systems we have created, are moving to a global and interconnected state. We were living in a society of independent nations that just focused on their own problems and deal with other nations as separate groups. As of a century and a half ago or so, the "independent" and "separate" aspects started to become more dependent and combined. Some people don't like this, and thus move against it (either actively fighting it or by refusing to participate). Other people take advantage of it, because global systems have not been properly developed. (The United Nations is not a world government, and if we were to create a world government based on any currently existing government of some country I really don't think it will work.) Other people are not aware of this. Lack of education is a good reason, either a lack because the country or its people are too poor for proper education or the country's government purposely restricts what its people learn.
What do we have as a result? We have some people operating at a global or macro level. NGOs and Multi-national companies are not thinking about operating within a country but above all countries. A multi-national can move its operations wherever because it is not limited to functioning just within one country. There is thus a major economic force acting upon the people in a country. How do people respond? One way is to go where there are jobs, or where one thinks there are jobs. Immigration has of course happened before, but my point is that economic pressures for immigration are now at a global level and not within one country anymore. People don't move from city to city looking for work, now people may have to move from country to country. That is a lot more difficult and more problematic, given the lack of a world infrastructure for such movement and lack of consistent laws or responses from different countries.
I think this is a reason why countries will have to deal with immigration, regardless of whether they want it or not. A country may want to close its borders, but in all practicality this is now impossible. There is external pressure to keep a country open to "foreigners", whether that be people, companies, ideas, etc. The concept of foreigner also only exists if our thinking is at a country level rather than a global level. Such problems may not make sense unless we think in sufficiently macro terms, and then look at the levels below. (And, of course, I can say "think globally" but such a statement on its own is completely unhelpful without providing any supporting frameworks and processes to actually engage in thinking at a global level.)
Just my two cents to this discussion.