Hiring a GameMaker developer is beneficial due to their specialized knowledge in this popular game development engine. They can efficiently create high-quality games, saving time and resources. Their expertise includes handling GameMaker's scripting language, GML, providing robust control over game details. They can also utilize GameMaker's drag-and-drop interface for rapid prototyping, making it easier to test and tweak game mechanics. Moreover, their familiarity with GameMaker's suite of tools can ensure efficient sprite animation, sound mixing, and networking capabilities. Hence, a GameMaker developer ensures a streamlined development process, resulting in engaging gaming experiences.