How you you propose they solve it? They cant implement renaming, and then still, who would have to do that? There's just no acceptable fix for it.

Is it anoying? Sure.
It it game breaking? Absolutely not.

Unless you are huge and special no one is going to seriously be refered to your FC since you're just one of the many many many FC's out there. There's little to no confusion. If anything, you wont even run into the people carrying duplicate names, you wont even recognize anyone with the same FC name because the Tags are diffirent entirely.

Now what -is- anoying is duplicate Company Tags on two or more large companies. Those show up next to your name and are for everyone to see. And most of all, those are easily confused. There's easily 5 Free Companies walking around with "Kupo" in their tag. 4 of those dont even have anything remotely to do with moogles, the 5th one does but isnt called anything it would abbreviate into... Just anoying.

Anyhow, long story short. Cant be changed, because someone will have to pick a side and end up changing their names. I dont feel SE has the means, time and desire to police all the FC's and their names.