How would you expect 3D Touch to work on a screen that moves if you press on it? You’d need to maintain the laptop screen in one hand while 3D Touch-ing with the other; that’s cumbersome.
3D Touch/Force Touch actually currently works on OS X on the 2015 MacBook Pro and the new MacBook. The touchpad doesn't move, it's just pressure sensitive and provides haptic feedback so you feel like you can depress it even more after clicking. OS X provides a dictionary/lookup popover when using it in Safari and some other apps.