Cologne attacks represent such a tiny fraction of immigrants. It’s like saying that 100% of Norwegian terrorist acts has been carried out by white men, and, therefore, Norwegian white men are all terrorists. Complety stupid.
The muslim generation (of which you can count the majority of immigrants to) is immensely more likely to be socially conservative, be it negative opinions on women's freedom or the acceptance of queer people and the jewish.
Why you think they would change their opinions just because they migrate to western countries is beyond me.
So, should one screen immigrants and only allow queer flag waving liberal progressives from SF in, or what is exactly your point? Many Germans would also not qualify if those were the requirements.
Isn't all of this stuff verging on thought policing?