I understand grind in an MMO, but this particular grind takes over a year minimum and that is if you have no-life and can be logged in 24/7 and get every single S-Rank ever. This is a far harder grind then even relic weapons were way back when in FFXI first came out.

A reasonable guess for the major player base would probably be threeish years at the current requirements. There is no gaurantee that the game will even be running still in three years with the way that the player base fluctuates so much after each expansion.