I like the idea of a justice system where all trials are public and you're tried for the crime you actually committed. But that ship sailed a long time ago, in the US -- it's something like 95% plea deals now. Only we pay lip service to old ideas.
Under the current system, it seems to me that plea bargains act as contracts "I agree to serve X years & not go to court", despite being phrased as "I admit guilt for Y crime" on paper.
Of course people actually convicted of crime Y also exist. I'm just surprised that this whole thread assumes that only they exist.