He really isn't giving up on this. His persistence is just like Roxas' with a hint more of optimism. Maybe like...Sora's. All of these similarities do become quite a headache after a while.

Seriousness is met with seriousness, relentless from different perspectives. It is only after a few more seconds that Xemnas sighs. "So you say. And perhaps it is true," he says, folding his arms over one another. "I will concede for the time being."