This game's failings all boil down to the lack of itemization combined with its rapidly vertical progression. Devs can only introduce a limited amount of new gear to keep the playerbase from gearing up too quickly, which relegates non-raiding rewards to cosmetics/furniture/junk that doesn't really appeal to most gamers. So even when the Devs attempt to make new content, people just aren't interested because the rewards aren't there, because the itemization isn't there & because things are obsoleted so rapidly anyway.
With a more horizontal structure (more itemization options and/or hitting the brakes on rapid vertical progression) the devs would have a much easier time getting players excited about new content.
I remember back in the Final Fantasy XI days when the release of patch notes (and data mining!) was viewed as a major community event. Players couldn't wait to comb through the scores of new items to see which ones might incrementally improve their stats by even the smallest amounts. Nobody expected new items that would dramatically obsolete older items. It was all about the smallest ticks of improvement, giving people goals to chase without making the previous rounds of gear completely invalid. (The little secret of FFXI was that anything could be beaten with auction house gear, and the fancy drops you got from Sky/Sea/Dynamis/etc. just helped you beat things faster or with different party makeups.)
I'm enjoying FFXIV for what it is -- a game I log into and play for a little bit maybe two nights/week -- but I frequently long for what it could be. For a game that tries so hard to cater to casual players, there's a shocking lack of social (Free Company) battle content that would allow people to build the kinds of connections that made previous MMORPGs so special. At this point I have little faith that this game will ever be more than it is right now.