...there are clear signs of the growing decay of manners, of youthful gangs terrorising public spaces, from stations to shopping malls. Mentioning this decay is often dismissed as reactionary...
Very strange to bring this up in the conclusion but never establish any of these facts previously. It's unclear if these claims are about France or the US or something wider. If anything, making broad, unsupported claims at the last moment and then using those as the motivation for your call-to-action sounds pretty "reactionary" to me!
Edit: I feel compelled to clearly state that I don't agree with the presumption that "youthful gangs are terrorising public spaces" or that "growing decay of manners" is either A) happening or B) a problem worth worrying about even if it is happening.