Also, where the hell you live that there are so many muggins, street and bully fights? All the while countless bullies are easy to fend off by junior trainees while the trainees themselves don't become bullies or something?
Cause as someone who done martial arts, it takes more of pure aggression to win against bully (or successfully bully someone) or in street fight rather then technique on junior level. And also that people training martial arts are no less likely to bully others then general population.
Moreover, majority of what is done and taught in martial arts lessons is not for self defense. A lot of it would land you in jail (cause it is about literally killing people), a lot of it is pure sport with little street fight application and a lot of if king of like gymnastics with no fight application at all.