Here's the thing: Everyone has been bullied at some point in their life. Not all children are prone to it, but there is always a bigger kid prone to intimidation tactics when growing up.
Kids live by the law of the playground jungle when adult supervision and rules are absent from the equation. It is ingrained into us as some form of social stepping stone, the animal in each of us at work, attempting dominance and security for an insecure bully.
There is a time honored civil process in which we attempt to retrain our young into civilized little pricks. Picking on the weak is wrong, and you don't get to take advantage of a fellow human because you're physically or mentally able to do so.
Everyone is small and helpless early, and many are old and helpless late in life. These rules benefit us all, and what happened here sends precisely the wrong message.
To quote the movie Paranorman :
Neil: Nah. You can't stop bullying, it's part of human nature. If you were bigger and more stupid, you'd probably be a bully too. It's called, survival of the thickest.
Profound.