Plea bargaining is more like a gambling buy out. Plea "guilty" and we'll guarantee you a lighter sentence, plea "not guilty" and be prepared for a long and expensive trial, but you might get out of it.

Actually, the trial judges in the U.S. have a pretty good reputation as far as fairness and incorruptibility (sure it happens, but it's not really common).

It's better than say Italy, which is considered pretty suspect or Japan, where you know the conviction rate is like 90%.