ArXive is a preprints' database, that is, papers indexed in it are not yet refereed. In that sense, papers that went through referees' examination are accepted as more accurate and reliable than papers that did not go through this process. Nevertheless, there are research groups that cite Arxive papers because they know the researcher and the quality of his work
It all depends on the discipline and the research groups that store their papers in ArXive..
Innovative papers, new dimensions and ideas are often discouraged!!! It's a typical human tendency. Under such circumstances the innovative papers first come to arXiv before they are finally published.