As another commenter has already pointed out, writing a scientific paper is not copywriting. It involves, at least
- Collaboration with other scientists. LaTeX is text-based so it can be easily included in source-control systems such as GitHub. This can also help attributing authorship to specific lines or chunks of code. Something you can't (easily) do using word. It also implies that some, or all, these scientists do not have access, or budget, to buy proprietary software such as Word, which means that comparison is never fair when one of the compared systems is not accesible to everyone. You'd be surprised to know that there are some scientists out there, myself included, who wouldn't be caught dead using a Windows computer and would have to go out of their way to use Word. We can use OpenOffice, but then some format things would go amiss since Word uses a proprietary format.
- Second, assumptions are false from the get go. You are comparing a word processor with a document preparation system. It would be fairer (but still not fair) to compare Word with LyX or MikTeX, including a Wysigyg interface, and which is, in fact, used by lots of scientist who couldn't care less about \begin{document} and $x=y+z$. Good thing is that the file format for these programs is pure LaTeX, which allows seamless collaboration with those that are not into WYSYWIG things.
- For the sake of fairness, you should have included also LibreOffice and maybe another wordprocessor, if only to affirm, that, if LibreOffice is closer in those results to Word (which it will probably be) how much money would have been saved by using free software as opposed to proprietary software.
- Some of us use literate programming with systems such as SWeave or knitr, and we can do that because LaTeX is pure text. You can also generate automatically tables, graphs using LaTeX own language, and, in general, lots of parts of the final paper. Including, of course, bibliography from bibtex files.
- Archiving. You can easily compile a TeX file from 30 years back. Good luck doing the same with any proprietary format.

In fact, my own experience when I have been forced to work with Word (otherwise, by my own choice, I would never have touched it) is that it's a nightmare to deal with bibliography, impossible to get the figures right when you want them, cumbersome to collaborate and a host of other things that make that we usually work in LaTeX, and, when we're done, convert it to Word.
Finally, it is really difficult for me to understand how this kind of paper could get through. Very few subjects, not a wide base for comparison (different versions of Word!) and considerations such as integration in a scientific workflow should have been taken into account, more than these, mostly irrelevant, measures.