These game servers are really the perfect use case for agents. Would anyone really care that much about code quality if the server works fast and reliably?
The number of implementations and the lack of success suggest that it is a genuinely hard problem for humans, and "agents" are not going to magically make it simpler. Unlikely that humans abandoned their projects (or failed to band together) solely because of their desire for code quality.
Software is genuinely hard for humans, and agents have made it simpler, not magically, but they cut complexity like butter.