I think the point you're making has some validity, but a plea bargain is a lot more analogous to an "out-of-court" settlement in a civil suit than it is to cont

I think the point you're making has some validity, but a plea bargain is a lot more analogous to an "out-of-court" settlement in a civil suit than it is to contractually agreeing to binding arbitration. That is, I cannot sign away my right to a criminal trial right now, not having committed or been accused of any criminal offense. Whereas I can sign away my right to a civil trial now, not having yet committed any breach of contract.