As an older gamer i clearly remember the olden times when getting to max level signaled the end of a game (or very close). Therefore I quite understand how you feel. Incarnates are not quite as daunting as you think. If you can craft IO's sets and gear up at 50 then you can do incarnates. If you haven't crafted and geared up well that's the next step after 50 (get Mid's, u will love it). Did you unlock all your costume slots? did you get the 4 passive accolades? Did you unlock every location in your long range teleporter? Did you create a SG for your roster? Did you create a base for your SG? While its not impossible to run out of things to do, 50 is not the end of the game.