Perhaps it is not unreasonable to ask this question, while noting it was a horrible action to that young man buy some disgusting thugs.

If the roles were reversed and the Middle East countries were economically sound and millions of Europeans began descending on these countries how would those generational Muslims feel in their homelands?  

Assume for a second the millions were admitted into the country, then when it came time and the newly arrived wanted to start changing things, building churches here and there, asking for special educational rights, what would the response be?

If you have arrived at anything less, than, "you know what, predominately white countries are the most accepting, while far from perfect, they have allowed us in when we never would have done the same.".    Or, "you know what, I should stay in my birth country and strive to make it better as opposed to flocking to a country that ideologically I do not share enough values with...to do otherwise is rude."