This is not based on any recent events I’ve been involved with; it’s speculation on how things might evolve.
One potential problem facing a juror might be that he doesn’t know what he doesn’t know until after the trial, if then. If it becomes widely perceived that judges can and will manipulate the verdict by controlling the evidence jurors are allowed to see, this will change the jurors’ behavior. Judges’ decisions about procedure and evidence could go both ways. A judge in one case might not let the jury know about material unfavorable to the accused, and in another case might suppress testimony unfavorable to the prosecution. If the system becomes visibly corrupt, with prosecutors abusing their discretion, lawyers on both sides deliberately trying to deceive the judge, jury, and public, and biased judges manipulating the jury, I’d become unwilling to convict anyone on the basis of what I heard in court. So we need to stop things reaching that state.
I’m conservative, in favor of law and order, and supportive of the police. I’d not be keen to have a guilty man get away with it. Even so, I’d rather that, than have an innocent man convicted. If things ever got to the point that we couldn’t generally expect justice from the courts, many people would conclude that the government had forfeited its moral claims on our deference. We’d be left with a society where people had no respect for the courts, and paid only pragmatic attention to the laws. The government could no longer rely on moral authority, but would need to enforce all the laws at the point of a gun. To prevent that, it is essential to maintain the integrity of the justice system. Justice must not only be done, but must be seen to be done, publicly and reliably.