This is something of a cheat post, because I am pointing you in the direction of a different article, but I thought it was worth posting.
The title is "Isil's Western converts are not motivated by Islam. They are
motivated by boredom." The article points out that many people joining Isil are not necessarily the ones you would expect and that often they are doing it because the western way of life no longer offers them something to live for, or indeed to die for.