Earlier quoted context omitted.
No, I think "it's natural" is a bad defense of both.
Trying to prevent small children from squirming and getting distracted when they are bored and don’t have enough active outlet for their energy is pretty well impossible. Even harder if the kids don’t get enough sleep, aren’t eating enough or healthily enough, have to deal with strong emotional challenges at home, etc. Kids are on varied biological rhythms, and some times a kid is in a place where they simply do not…
The idea that you should stimulate kids to the point where boredom is impossible, or that we should excuse harmful behavior if the kid was bored / upset, is just silly. It only sets the kids up to fail; to live a life where they can't focus on tasks and they lash out whenever they are in a bad mood.