You would have to give a case in point to get any kind of meaningful answer.
Often the public knows things that the jury never hears so while very few of us don't believe that OJ did it the jury wasn't convinced. But we still do, and probably always will, believe he is guilty.
Of course it goes both ways. There was a man convicted for growing marijuana in federal court. The jury was never allowed to hear that he only had a few plants and were led to believe he had a vast farm. The jury was never allowed to hear that he was growing it under contract to the County of Oakland for research. The judge in that case blocked all evidence that would have gotten him an innocent verdict.
Some might say that we shouldn't be judgmental but that is really just a cop out. Should we not judge Hitler, Stalin, Poe Pot, W Bush or countless others? Should we not judge sex offenders or pedophiles?
The fact is that life is really one big judgment and we have to make calls everyday. Calls about people and things and we tend to be cautious, for good reason. It is usually better to be harsh in that judgment than lenient, better safe than sorry.
At best we can try to be well educated but we will always be judging everyone and everything around us. That is a good thing.