Face ID makes less sense (or seems less advantageous) to me on a MacBook than it does on an iPad or iPhone. Face ID on an iPad or iPhone could be an advantage in one-handed use applications, and you're usually going to be facing the iPhone/iPad anyway from the start, while, for a MacBook, you're either always going to be touching the keyboard anyway so why not start out with touch ID, or you're going to be using it in clamshell mode and won't have access to the camera...
Having said that, I vastly prefer touch ID on the iPhone/iPad, as touch ID is too limiting sometimes. I can't unlock it with a finger when the phone is stored away from view, especially when driving. But you know Apple...aways have to remove "something" physical every year or two under the guise of giving the user something new, only to backtrack 50% of the time after realizing their error.