Mosiah continues with the bad example set by Noah. Because of Noah’s actions, his people were brought into bondage to the Lamanites. It was a long and difficult process of repentance that was required before the Lord delivered them from bondage. The point is not so much the bondage, but the way in which that might have been prevented.
Mosiah declares that the problem is trying to remove a king. Since a king rules by the presumption of inherited right, there is no mechanism to remove a bad king that does not result in the “shedding of much blood.” Thus, the cure is possibly as bad as the consequences of remaining under the rule of such a king as Noah.