Turing-completeness is not just a benefit, it also puts a huge maintenance cost on you. An S-expression is something you can edit in your level editor, process

Turing-completeness is not just a benefit, it also puts a huge maintenance cost on you. An S-expression is something you can edit in your level editor, process with a script or do a lot of fun stuff with. It's just data. You can even convert it to JSON, XML or binary if you ever get tired of S-expressions. Once you are no longer dealing with data, but with actual Scheme code that is no longer the case and it becomes virtually impossible to do anything with the code other than directly editing it in a text editor. It's extremely inflexible and every tiny API change will break everything with no automatic way to fix it.