I think Brown said it best and it all really comes down to what you want for your kid since every style has its purpose. You don't want him to be a bully but at the same time you don't want him to be reluctant to fight. I think martial arts puts a ton of hesitation on a kid, based on the values they teach. That's just been my experience though. I went to the same dojo for over 10 years and it was strictly a Japanese dojo. The instructor barely spoke English.
My father for example, he's been doing it his entire life. He was an instructor in Italy for 12 years. 3rd degree black belt. At the same time, he would never hurt a fly and the end result is people in the real world walked all over him. I think that "inner self confidence" hurt him in the end when it came to things like business, family, etc.
I've just never agreed with the "I can defend myself, but I am going to avoid the fight" mentality. I used to have it and it never paid off. I was always holding back because I didn't want to hurt the guy. Given that the majority of the time I never even had a choice as to whether or not I wanted to fight anyways. Thankfully I've never been beaten up, jumped, etc.
We're older now though. I'm 28. I'm just speaking in "what I would want for my son", the same way you are. For me, my kid is going to strike. I feel safer that way.