I agree completely. DVCS are useful for plain text, which for almost anyone except programmers is only a tiny portion of your data. Using git doesn't gain you anything, because we can't use diff for ODF etc. What we need is pretty much a drop-in replacement for dropbox.
With all due respect, this seems the expression of a sort of narrow-mindedness typical of programmers. People who work with source code all day assume that code is the model of computer work. However, code is actually very particular. What we really need is a place to store our letters, PDF forms, spreadsheets and so on, which are quite different from code in many respects.
The situation is similar in the field of text editors. Here every week or so someone starts a new editor which targets ... programmers. But there still is hardly a single text editor which is any good for writing simple English language prose! Here there is little use for syntax coloring, line numbers, nonproportional fonts. Instead you need configurable line spacing, easy-to-read proportional fonts, paragraph-based (not line-based) navigation, word-wrapping, etc. Still instead of solving this very real problem, people come up with new solutions to already solved problems.