Maybe she is used to it? I have used track changes and it is good and all ... but it may not be exactly the same as being able to know where and when a change was done, by whom, and with the reasoning sometimes added with it that comes from VCSs like SVN and GIT.
I think that's the point - if you use these things expecting them to work like a revision control system for code you'll be disappointed and frustrated.
Meanwhile, people who have no such expectations cope perfectly well.
