its not as simple as that, clearly you havent been in the situation of being bullied yourself or atleast not a serious one.
if like me, at school you had a heart problem and one punch in the chest could result in hospitalization you'd think twice about "punching them in the face" or if there are more than one? maybe 4/5/6 of them holding you against the corner? then what..? punch them all and walk away a hero? no. it doesn't work like that.
the guys that picked on me, some of which are now drug addicts (ha!), were the 'popular'... them people with tree trunk arms and six packs from the start of year 7.. if i went and punched them in self defense i'd of got my face painted across the wall.
so no, that tactic doesn't simply work as good as you put it.
