I assume with your nick you are LEO. As you know, almost every department requires handcuffs across the board during any arrest. You also know that the police are simply following orders and have no say in and if they can arrest in situations like this.
Yes it look bad placing children in cuffs. Yes it does not do much for community relations, however, these officers are following standard officer safety rules and should not be slammed for doing their job.
LOL, no, I'm one of those evil biker guys...the name comes from my army days, but after living under rules and regulations that I sometimes found....um....difficult, I can put myself in their place, and can emphasize with them.