the lack of compatibility with the other MS Word document formats and the fact that the latest versions of MS Word do NOT open the earlier versions properly. Some will IF you find and download special add-in, but it should happen out of the box, and the only reason it doesn't happen is because Microsoft have deliberately introduced changes to stop it happening and to force software upgrades - ie for their profit and not customer usage.

Now, I don't know what it's like where you are, but in many industries legal contract often run for multiple years, seven or ten or fifteen years can be common. For other legal reasons all the documents involved in the contract negotiations etc need to be kept in their original format for the life of the contract and past the time of the final payment in which a challenge to a payment can be made - sometimes for seven years beyond that. It was document in this class that I was having an issue with.

Now, you seem to think Word 2010 and Word 2013 are perfect or close to it, try opening documents saved in Word 2a, Word 6, and Word 97 in these last two versions of Word and see if they open properly or not, and if they get changed by MS Word when they're closed. Word 2007 couldn't do it, and the few I tried in Word 2010 got screwed worse than in Word 2003.

It's this incompatibility that requires people to retain earlier versions of Word, and the differences in the way the latest versions look, feel, and are used upsets some users as well as most people are only happy and comfortable with what they're used to using. Which is why some companies don't like the ribbon format.

Edit - Oops, forgot to say:
The problem with not perfect format layout between MS Word and any other software is solely due to MS NOT using the Industry Standard layouts and instruction codes, so again, the issue is due to deliberate design decisions by Microsoft to NOT play with the rest of the world.