Every New MMO launches with either No or Limited End Game Content. Very Few games get an End Game Content boost 3 months after they are released, and planned Content releases on the same period... In any other game, when they release a new class, you'd need to create a new character (and pay more money). In ARR, when a new class comes out, JOIN IT'S GUILD and Rock On!

Just because you hit 50 doesn't mean you're out of content. Have you mastered your class? (Most FATE Grinders have not)
Have you gotten the Crossclass skills that carry over to your Job for maximum damage output?
Do you feel the flow of the water, wind, and earth as a Conjurerer (and pray to the Twelve that the next Job Patch adds GEOMANCER as a DPS Role for CNJ, with it being CNJ 30 + THM 15)?