Couldn't disagree more. By this logic, no country should criticize any other country's courts and justice systems because they all have problems and massive miscarriages of justice.
Do we want more scrutiny and criticism or less? I think the world is better if the US and UK aggressively criticize and pressure other countries to improve AND ALSO everyone else criticizes abuses by the US and UK and pressures them to improve.
IMO that is a much better world than one where nobody is highlighting abuses or asking anyone else to improve.