It is easy to tell people what would work with your own children because a person knows their own children, what they weigh, how far they would go, what kind of injuries they have had, etc. And most people who are posting about how they can handle their own children are not taking into account the fact that their own children would a) not be behaving as this child was (most likely) and b) would probably be less likely to harm their parents than some cops that they just said "come get me ****ers" to and c) the cops would not have much of the information I mentioned above.
This was not a small 8 year old. (You can see him in the interview he did posted earlier in the thread.) He was armed with something that could have cut or stabbed the police if they physically went for the kid. And even if they were able to avoid injury to themselves from the kids weapon, they could have still hurt the kid by trying to wrestle him to ground in trying to subdue him. Kids do not think and act like adults. Kids, including 8 year olds, are likely to keep fighting the cops even if it means they may get hurt. Using pepper spray has been shown to be very unlikely to cause any permanent injury to the person being sprayed. Can the same thing be said about using force, especially against a child?
I don't approve of using pepper spray to stop a child from doing something "bad" under normal circumstances, and I would say that almost any child's actual parent could probably find a better way to stop the behavior. But this was not a normal situation and it needed to be dealt with more quickly than waiting for the kid's mother to show up to try to calm him down. Using pepper spray was the best option for the situation at hand. Waiting it out would have probably worked too, but it would have also wasted a lot of time while the cops had a group of scared kids and a teacher trapped in another room and the kid was already breaking things and threatening the cops. Plus, I wonder if the kid might have learned a lesson from being pepper sprayed better than if they would have just waited for him to calm down on his own or his mother to try to calm him down (or at least if he might have learned the lesson had his mother not paraded him through talk shows as a victim).