Law derives from the Constitution and from statutes passed by legislators. If you want it changed, go to the Legislature. Courts do not make law. They interpret it. But in the process of interpretation, of course, they flesh out and add to the body of law.
Decisional law is a major component of the law.
The exclusionary rule is one of the most famous examples of decisional law. Where there was no remedy at law and the legislators did not move to create one, the judges took it into their own hands to do so. That is a gross misstatement. Judge-made or decisional law is an integral component of the rule of law. The real issue is whether the courts overstepped the bounds of interpretation on creating the exclusionary rule.