Except they're not being segregated, not in the least. There is no region locking, there is no "YOU CAN'T PLAY WITH THESE PEOPLE!" You pick what server you want to play on.
How people keep missing this point is beyond me, apparently basic reading comprehension is outside the capabilities of most people.
What SE is doing is in now ways segregation. Segregation belies lack of choice, of which there is none. If you want to play with a bunch of people that you can't actually understand, such is your choice.
And while we're at it, global servers are hardly unique to FF. I have met more people in more places on shitty F2P MMOs than I had in 6 years of FFXI and my time on FFXIV combined.
Being multi-national is in no ways unique, and this "feature" you're talking about isn't dying in the least. Please make use of more of your brain cells before making conclusions.