http://www.hd.square-enix.com/eng/ir/
I got my info from the investor relations reports, and balance sheets. They aren't the most reliable, by far, nor are they for only ffxiv, however looking at the past few quarters has showed a decline in profits related to subscription rights (earnings, page 9, 3/4 down the page). I'm not saying thart the game is only losing players over minor QoL things. there are a lot of reasons why the game loses players. a lack of continued interest things to do, a lack of community interactions outside of instances, and a lack of casual friendly endgame products, for example. It happens to a lot of newer MMO's, and im not faulting FF for that, but it happens..