Your reply was too interesting not to try to answer :)
> I'm curious on what basis you chose the group that you care about? And do you really care about them?
I have two answers for this
1)
It is not that, say, I care more about the danish than the syrian.
It is that I find sad that a culture would decide to implode, no matter what culture it is.
This works on a set of assumptions, all of which might be false, but are justifiable (it seems to me) if not correct (for that is harder to predict)
* Receiving a big influx of immigrants that are 20 years or older
* Having them and their descendants compose the bulk of your population after a certain year (say, 2070)
* Those 2 points significantly affect the makeup of a culture
And moral weights:
* That the existence of a culture itself has moral weight comparable to the well-being of individuals
---
2)
There is also the perhaps more immediate issue:
If indeed immigrants make the largest part of the population of a country when you are old and need help, can you *really* keep them from voting in a pattern that reduces your ability to get help? For example, from taxing your accumulated wealth now that you are no longer working, or to cut your benefits.
This fear is not unreasonable, and one might be saddened of the (apparent) shortsighedness of not addressing it. Or angry (if one thinks this will happen) that the current middle class and poor of the european country are being sold out by the rich of that country -- they get more labour today, and to live confortably in their old age.
Again it is a matter of weights, you can think that the increase in welfare for the immigrants in question outweights (or even far outweights) these costs and risks (one is a cost only if you value the culture independently of the people, another is a cost only in a probabilistic sense). But neither is absurd on the face of it, and it seems reasonable to be sad that "a culture is doing this to itself".
--------------
The point here is to establish a degree of reasonableness to the other side, so that both sides can start to reconcile their values rather than dismiss them, not to state which side is right (a thing that I frankly do not know)