You know, some of this is not so different than what they used to say about Jewish refugees in WW2, when the concern then was Anarchist Terrorism.
Jews were look for a safe place to Iive in peace and security where they could practice their faith.
Jews did not come as terrorist but builders and investors. They came to improve and modernize, to share their knowledge and skills. They were greeter by some with abuse and death.
Some even suspected them as german infiltrators and not as refugees.
Now muslim are seem as infiltrators because a large percentage of the refugees are infiltrators and not refugees. They need to be vetted and those willing to work and improve the countries can be given entry, but those who want to bleed the countries and cause harm should not be given open access.
It is not about being mean but being smart and careful.