My theory is Hubris. MS is such a behemoth that if MS Word doesn't work for a few thousand users, then it doesn't really matter to them, since millions of others aren't complaining. We simply don't matter to them.
For a while, an MS tech was working on trying to solve the problem for us, but after every thing he suggested failed, over a month ago, he has simply disappeared. I suspect his supervisor told him to drop it.
For now, I'm using Pages and occasionally MS Word 2011. Maybe that long lost tech will come back to us with a solution. But I'm not counting on it.