Yoshida pointed to three main reasons for Final Fantasy 14's failure in that first form. First, the team had an "unhealthy obsession with graphical quality." In a series of videos comparing the original version of Final Fantasy 14 to A Realm Reborn, he showed that the core game may have looked slightly better, but its areas were also empty and it took up a lot of processing power.
For a specific example, Yoshida showed a screenshot of a flowerpot outside of an inn in the first form of Final Fantasy 14. He called it "the loveliest flowerpot in an MMO," but then revealed its heavy cost: That single flowerpot contained over 1,000 polygons and 150 lines of shader code, meaning it took up as many resources as a single player character.
In order to accommodate such heavily detailed graphics, the original team made compromises that went against the reasons why people play MMOs. For example, they limited the number of player characters on screen at any one time to 20. While this allowed the game to look beautiful while still running, it lost sight of how great it is to log on to an online game and see dozens of players running around at once.