Publishing Scientific Experiments

Researchers at Stanford investigated the fate of 221 sociological studies conducted between 2002 and 2012, which were recorded by Time-sharing Experiments for the Social Sciences (TESS), a US project that helps social scientists to carry out large-scale surveys of people's views. They found that only 48% of the completed studies had been published. So, my assumption is that 52% of the studies did not give the results the researchers hoped for. 

However 20% of these "failed" studies did reach the publications stage, but 60% had not been written up. In some cases the studies were not written up because the researchers felt they would not be published. Would it be worthwhile for researchers to know that some ideas have already been tried and failed? Or, should be informed only of successful experiments?