Then you would be very suprised at a lot of what happens in game dev. Many in-house tools are mere skeletons, fleshed out just enough to get the job done. The bug squashing is focused on the primary product. Developing end-user ready tools is basically a paralell dev process. Difficult, rare, expensive but often immensely valuable and rewarding.

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.

A tool that works perfectly fine internally but is risky to release publicly doesn't make it a bad tool...