That's not to do with "modern times". It's to do with the shitty parenting that caused this in the first place.
Of course it has to do with "modern times". Don't worry, I'm not judging how you personally raise your own kids, so no worries. Can't tell me the kids aren't more ruthless cunts than they were 20 - 30 years ago though.
Want to know what would have happened if I did that when I was 12? Would have went something like, "Hey, dickhead! Think you're a tough guy because you can pick on an old woman, eh? Why don't you try picking on me, you fucking pussy?!?!" -- *bam* -- square in the noise. Then when the teacher asked why I had a black eye and blood on my shirt, I would have said I tripped, because I'd be too embarrassed to say the truth. The teacher would understand this, grinned knowingly that I learned a valuable lesson that day, and moved on with the day's class.
Or if I had gotten away with it, my dad wouldn't have apologized to the old lady for me. If anything, my dad and the old lady would have become friends, as they ganged up on me and made my life a living hell for a couple weeks.