It pops where your camera is pointing, and typically most people don't play with their cameras pointed at the floor. There is a small blue dot that appears in the center of the screen when you use floor-targeted skills like the caster limit break to show you where you are aiming, I guess you just didn't notice it. Maybe they should make it flash or something. Hell put "target aim" under it and maybe people will get the picture a lot more quickly lol