This is the rule in game development rather than the exception. It's why polished commercial engines like UE4 and Unity have been so successful. In house tools

This is the rule in game development rather than the exception. It's why polished commercial engines like UE4 and Unity have been so successful. In house tools even at some of the biggest most successful game developers are rough and undocumented. They are also generally made by engineering teams an order of magnitude smaller than Unity or Epic.