Peer review is regarded in the scientific community to have an important function within the scientific method in that it is carried out by experts and "ensures that only high quality research is disseminated and available as a body of scientific evidence.  Such evidence frequently becomes part of mainstream thinking and practice, so it is vital that conclusions that these are based on are the subject of valid methods and accurate presentation."  You know, so less informed people don't make unsubstantiated claims that vaccines cause autism, for example.