I'm not saying that there's no cases where striking back is unwarranted, either. I just don't see it as a viable solution for the overall problem of bullying, as a whole. I struck back when I was bullied, and it just made the bullying worse, plus got me in trouble for being violent because the bullies were smart enough to wait until the teachers weren't looking, so all they saw was me having (apparently) struck first. This started when I was six or seven. I spent most of elementary school in a classroom for people with behavioral disorders, because I had a hair-trigger temper from how frequently I was bullied. I had less than half-a-dozen friends from that entire horrible time, not counting friends of convenience (people who were friendly enough alone but participated in the teasing in public) who I quickly learned to recognize and avoid. For that matter, I had less than half-a-dozen even counting friends of convenience.
I almost became what other people expected me to be, largely because I struck back and struck back hard. The only reason I avoided it is because I realized that I had seriously hurt someone who's only real crime was in going along with how everyone else treated me, who was terrified of how viciously I'd learned to react to teasing but didn't know any other way to react to me. Mean, vicious, and nasty could all have been adjectives that people described me with before I even officially became a teenager. I was a bundle of pissed-off fury primed to go off if someone so much as looked at me the wrong way.
But that wasn't me, that was the face I had never realized I was presenting to others. And when I did realize it, I made a firm commitment to myself to change . And I succeeded, though it was a long and harsh road to walk, and one I had to still walk mostly alone till long after I graduated from high school. I don't have visible scars from then, but they're there, on the inside, etched with acid. They still hurt. Two decades later, I'm still aching from the wounds of that horrible time.
So while I can understand that sometimes, there may be little choice but to hit back, I categorically do not accept that hitting back is any kind of a long-term solution to the problem of bullying. It comes too close to making the victim into a bully or worse. Most real bullies, the ones who do the worst harm, are the ones who've suffered such deep and terrible wounds that nothing matters except feeling something other than the pain of those wounds. If we want to really fix the problems of bullying, we have to break that cycle, and that means not making their suffering even worse than it already is. It's true that if someone is already that broken, that you might have to inflict more pain to set things right, just as someone might have to re-break a bone that wasn't set right. But the person being bullied is the absolute last person who should be making that decision.