I can't help but think that most of the people on this thread are complete ignoramuses that simply do not understand how the development pipeline works. So yet me educate you.
Keep in mind that I too have not been able to play for days, and my ire meter is broken, twitching on the floor over there is a puddle of pure rage, so I get the frustration.

That being said, Square-Enix can't just twitch their nose and poof servers into existence. NOBODY STOCKS SERVERS!
Every server is custom built for purpose, which are not only expensive in and of themselves, but often times have a several year contract attached to them. And so they are tremendously expensive, so you only get them unless you absolutely sure your going to get full use out of them.
Obviously SE low balled their estimation of their player base, massively so, and believe me they are in a mad rush to get thous servers built and hooked up as soon as possible.