It is totally true that gamers (especially FF fans) don't know what they want.
Pre FF13 games were all on PS2 and PS1...
Of course tastes change given how much innovations has happened since within the game industry.
You really can't blame fans of FF to expect something more from the game given the series' history of pushing the boundary of what's possible with the medium.
Many examples of which were given in the posts above.
SE only has themselves to blame for falling behind of the curve. GTA3 was released in 2001, same year as FFX. Skyrim was released in 2011.
10 years went by without major change their interpretation of RPG.
This new entry lacks vision, and it is a question if the game can compare to the standards set by highly matured open world games such as GTA.
In fact, even the RPG genre itself has evolved in areas such as quest/character progression and combat. Going by the information that has been shown thus far, not only does the current combat system compare poorly both in its action and strategic gameplay, the game seems to have failed to innovate on the staples set by the series itself.
There are surely a large number of fans who care little more than that the game is actually coming out, and that may be all that matters.