You've never used ReST but you somehow know it's not good for typesetting research papers?
On the other hand, TeX was developed by Donald Knuth, a guy who spent his entire life doing research and writing papers about it. It has excellent math support, and is a true semantic language. I've written a few papers in TeX and been very happy with it.
Anyway, if RestructuredText were good at typesetting research papers, there would be no need for this project, would there?