That “radicalization” crap is just that, crap. A muslim is a muslim the commands for them to commit murder and mayhem is in their book in plane language that a kindergartener can read and understand.
We should ponder the question, not of why so many Muslims DO go on these rabid jihads, but why so many refrain.
Part of it could be the restraining power of the actual God. Because of this God’s light, those Muslims do not see the sense of actually living to the Koran. There are nice things about living on earth rather than blowing yourself up for 72 virgins. Part of it could be plotting on the part of Satan, who “waits for the opportune time.”