Just hours before the attack, Hollande said populism is the real threat
Yeah, perhaps to his regime, but not to the (real) French citizens. Populism is the solution to France's real problems.
Looking back at the past 40-50 years, the problems in the West started with all of the welfare and unions that the Left used as bait to obtain the support of the then, nearly all-White, all-Christian populace. Originally, much of this populace were culturally-conservative, but just wanted fairer labor laws and economic opportunities. After this populace became dependent on this welfare, and their unions,
the Left then started to fold in their cultural agenda as part of their platform...feminism, mass immigration, LGBT "rights", etc., stances that the original populace were opposed to but looked the other way so they could continue to reap their perceived economic benefit.
That's how I see it, at least; and once you can define the problem, the solution is relatively simple, but just difficult to implement.