What would you use a "git for data" for?
Although having said then when you say data to me, I do imagine some level of immutability. Logging scientific results using git would be pretty good if required, in the sense that there is a habit to just use folders and text files which is fine at the time but is really really hard to take over sometimes (Like code written by scientists with their single-letter variable names and hatred of functions, in my experience of Fortran - yuck)