What are the disadvantages of statute law?

Since for law to become valid it needs to go through a series debates and stages...if it fails at a stage it cannot be implemented as law. Sometimes good laws are rebutted. This complex system makes it hard to actually and successfully implement laws. Too many hurdles to cross. Also the actual debate may take years before they can come to an agreement...this causes stagnation of the law...And law implementation is a lengthy process.

The following applies to countries under a Parliamentary-rule form of government;
Parliament sometimes when making laws are not precise on what the law means and the law does not reflect their intentions. They sometimes do not word the law properly and as a result is open to many interpretations.
Since parliament is the supreme law making body, and it is the courts job to give way to its intention, defective laws have to be followed and the courts cannot depart from the law or it will be in breach of Parliamentary Sovereignty...therefore defective laws produce or result in unfair outcomes.