Bond rating is literally a speculation. Government body would need deterministic definitive rules to assign bond rating which would immediately be gamed. The id

Bond rating is literally a speculation. Government body would need deterministic definitive rules to assign bond rating which would immediately be gamed. The idea of having private firm do speculation instead is that if they are not good at it then people will stop using them and strongest would eventually survive. Unfortunately, they are well enough "protected" to go away.