One of the most common reactions to the requirement of a Professional Studies Paper in my institution is a groaning, "but we'll never publish that--and my boss will want short memos with the bottom line up front.' While it is excellent when student work does get published, the real value is in using the process of writing a research paper--framing a problem in a properly scoped way, looking for information, evaluating that information for bias and expertise, arriving at an answer represented in a thesis statement, and then using information to support that thesis in a coherent and accessible way.
All of our PME students are expert senior leaders, who are used to applying these skills quickly in a field where they are familiar and practiced, and often conveying the information in person. Their next jobs are likely to involve a steep learning curve of broader responsibilities, along with the necessity of their ideas moving up the command chain without them on hand to defend them.
Because of these practical realities, research papers offer a way to hone these skills in a controlled environment, with consistent feedback and guidance, so that when called upon to render a solution in a memo, the lessons of the more thorough, paced and peer analyzed work is a mental habit.