Because SE hasn't advertised the game since, well, ever. They had that Japan-only live action trailer and Yoshida's 2.0 announcement media tour but to bring in players advertising needs to be persistent.
I know all about Rifts patches and I've never even bothered with even the free trial of the game. How do I know about it? Rift has a persistent marketing campaign for each and every content patch.
Even Blizzard still advertises the crap out of WoW. My Grandmother knew what WoW was and she didn't even know how to turn on a computer.
SE isn't advertising 1.x and rightfully so, it's just a pacifier for dedicated fans. That's why Yoshida went on a media tour to talk about 2.0, and why the E3 trailer will be 2.0 only. 1.x is dead to the general gaming community.
Most gamers don't know about any of the changes to 1.x because they aren't wishfully checking Lodestone in hopes of the patch that will bring them into the game. They've moved on and will stay away until SE puts it infront of their faces and shows them why they should spend their precious free time playing XIV instead of WoW/Rift/SW:TOR/Aoin/Tera/GW2/Blade & Soul/DC Universe/Dust 514 so on and so forth.
Not to mention a lot has changed since 2002. MMOs aren't the only way to play with friends anymore.
They're not "future proofing" it because in about nine months it's all getting deleted.
We have a few months to gather Darklight gear, then a few months to farm Garuda weapons(1.22), then a few months to witness the Seventh Umbral Era events (1.23) that will change the face of Eorzea. Then it's 2.0 time.
1.x is only to keep us busy till 2.0. They said even the primal battles will be different in 2.0.
They won't advertise this game much till 2.0 when they fix the bad UI and the interface lag and the struggling engine and crippled servers.
You put your full creativeness into a project by being a professional and doing your job. I have no dobt Tanaka's original vision could have been an awesome game. And he did have the rug pulled out from under him. But that said, 2002 gameplay won't sell a game today. XIV needed to be something fresh and still does.