Many organizations today utilize projects as a strategic tool to achieve business objectives. As a result, project success becomes critical, making project management a crucial function in an organization. The project success rate globally has not been improving, and project management maturity models (PMMM) are now being further scrutinized. The PMMM is struggling to claim its value toward project success despite its success in the IT industry since its inception in late 1980s. However, since 2014, its publications have been on a decline. This paper attempts to investigate the reason behind its decline. Based on content analysis, information from previous studies was gathered and then combined so as to identify the possible cause of this decline. Three remaining issues leading to its deterioration were detected. It is -PMMM too-best-practices-centred type of model, inflexible, too complex, and plagued as an inadequate assessment tool. These issues have caused the PMMM to be a "hard sell" to the industries. The outcome derived contributes to a better understanding of the issues causing the decline of the PMMM in publication. Although once considered a successful tool for improving project success rate, the PMMM may become defunct in current project management environments without continuous research and improvement.