The answer seems to be that Microsoft doesn't want to be bothered with those of us who have to deal with documents initially created by other users who may not want to update to the latest version of Word. As a copy editor, I find 2007 much easier to use
than 2013, but I'm stuck with 2013 at the office. The colors in track change in 2013 are a real nuisance, usually starting with one color and then adding as the next color the one closest to it (turquoise, followed by light blue, for example)--as if the whole
point of different colors wasn't to see quickly who made what change, instead of going through several paragraphs before realizing that what appears to be one color is in fact two, and having to go back through the material a second time. And the idea that
when a user closes and saves a document, takes a quick break, and reopens the document (all on the same machine, with nobody else having gotten on, and certainly not changing user ID), that person will want to appear as a different color but still as the same
user is ridiculous. It doesn't seem as if there's going to be any help for these problems, which take up quite a lot of time and thus cost the user (in my case, my employer) money.