“Why should my son join scouts or stay in scouts?”
That’s a question I’ve heard many times. I always answer with something along the lines of: to help them become the absolute best person they can be. Now, there is scientific evidence to back up that statement. 
Tufts university conducted a 2.5 year study comparing cub scouts to non scouts and found some very interesting results. Read all about it at http://blog.scoutingmagazine.org/2015/10/22/tufts-study-confirms-scouting-builds-character-six-critical-areas/.