Why is --nolayout needed?

[osa1]

From the book:

In order to facilitate code generation or source code compression, compilers are also required to support a mode where the layout rule is not applied and no braces or semicolons are inserted. A recognized command line flag for that mode should be --nolayout.

I don't understand why this is necessary. If I'm generating Koka code I can generate it with braces and semicolons and no layout tokens would be added by Koka. Why do I need to explicitly tell it to not add layout tokens?

Given that Koka doesn't have this flag today, I'm wondering if this is from a previous version of the layout rules where even with semicolons and braces the algorithm would be adding more semicolons and braces?