https://bugs.winehq.org/show_bug.cgi?id=54550
--- Comment #3 from Zeb Figura z.figura12@gmail.com --- (In reply to KOLANICH from comment #2)
And, BTW, why are we using a text format for hives? I guess to allow easier editing and debugging... But why not to use the same format used on Windows (to get the compatibility to the software working with the files directly, and, maybe, better efficiency in reading/writing) and expose the human-friendly representation via a fuse fs?
I wasn't around when those decisions were made, so take my answer with a grain of salt, but I suspect it's a matter of nobody ever needing to use those tools, plus binary formats just being generally more difficult to work with in various ways. As you say, text files are easier to edit (both by hand and in our registry writing code) and debug, and not committing to the Windows format also removes the need to research and match that format, or to implement every feature at once. (E.g. we've made multiple changes to our registry format over time.)