The allegations seem to be mainly valid.

What the victims have been doing (in some cases for many decades) all the time? Why they did not contact the police and kept silence?

Because they were kids? In the more-or-less total power of the representatives of the sort of god who sent you to hell for calling the cops? Because of all the normal factors that keep victims of sexual abuse quiet: abuse of power, social pressure, shame, blame-the-victim bullshit,  people asking why they didn't do something at the time and casting doubt on their stories without even doing any checking.