Isolated incidents warrant condemnation and interventions to prevent them happening again. Systematic targeting of children, authorisation of the use of sniper fire against children who pose no realistic risk of harm, the use of children as human shields by armed soldiers, the torture and sexual abuse of children in detention centres, etc really should be unacceptable regardless of the ethnicity of the children.
Soldiers are authorised and even specifically ordered to shoot children. Soldiers have confirmed that they were given orders to do so. The patterns of gunshot wounds on child trauma victims in Palestine is highly consistent with this being a standard military tactic, to target children specifically and repeatedly.
I've been the first person through a door in an unpredictable situation where you don't know if there's a weapon on the other side. It's kind of scary as an adult with a degree of experience. It would be terrifying for a child. Using child human shields to go door to door is horrendous. It's a form of torture, really, to put a child through that.
Children in detention centres have not necessarily done anything wrong, and even if they had, even if they had definitely broken a law, that would not excuse institutional torture and sexual abuse. Prison is extremely scary for a child - where I live and work, nobody under 18 is placed in prison as there is evidence of significant harm where that has happened in the past. Children detained in Israel don't even have the same rights and protections as they did here, in a country where even those rights and protections were deemed insufficient to safeguard children.