Why not just make a PDF if all we are doing is sharing a view-only document?
To me, the idea that someone would pick up a complicated document like this and edit it in the Word web app is laughable. If I was tasked with editing this doc, I would edit it in the desktop version of Word.
The fidelity argument will only go so far. Someone out there might be impressed that Microsoft managed to have fidelity between two versions of the same product. Given the history of compatibility issues between versions of the Office, I am a bit surprised actually.