WiX basically lets you directly write the internal data structures used by Windows Installer to run the MSIs. Just in XML instead of some ancient binary database that is used in the MSI files to store things.

So the actual "byzantine incomprehensible mess" (which is indeed the correct description) is the MSI format and Windows Installer, not WiX.

I mentioned this in another response:

> Our primary goal with the WiX Toolset was to provide access to the full power of the Windows Installer. Given the adoption by extremely large software projects, I think we've done pretty well toward that goal. We're slowly turning our attention to simplifying the toolset to make it easier to use for simpler projects. But that's only been a focus for the last couple of years, so not a lot has come about, yet. But the Files element is a huge upgrade.

There is definitely more we can do to make simpler things simpler. :)