There are a lot of no-DirectX operating systems out there which do just fine. Although there is a long history of releasing Windows with DirectX, those versions of DirectX were pretty limited and installing the newer (more powerful) versions used to be only optional, on a per-need basis, before Windows got bloated. Considering that the ReactOS Foundation does not take decisions in the same way as corporations do, it's possible for DirectX to become again just some install-able frame-work (or frame-game if you will). So, DirectX may not be so badly needed as you imply it to be.

EDIT: Somewhat related - regarding OpenGL, ReactOS' decision was to bundle only the version 1.4, because installing the graphic card's drivers will give you exactly the last version of OpenGL your card can handle, that is - if you'd be interested in accessing the card's capacity (beyond what the default bundled ReactOS driver will give you) in the first place. Many folks might not even be interested in such a thing, considering that not every one plays hardcore games, so why bother? Why bloating the entire system with something that can be left as optional?