The problem we have here is that many people generally don't understand Jihadi mentality. They believe that it is a failure of a society to welcome in new people that causes them to feel alienated and strike back at that society, when in reality it is violent beliefs and scorn for the culture that a person brought with them or was impressed upon them by their parents etc, that causes them to become Jihadists.
If you blame the host country for problems, then there is no problem taking in more people from that area. If the problem is with those people, then you can't. So its a reverse-engineered logic for a faulty premise.