This function is available on the front-end submission form. I don't know why it's not also available on the back-end.
If i'm adding a new event, and in the middle of filling out the form I realize that this event is at a location that is not yet stored on my website. I now have to cancel & go create that location under the locations tab then attempt to create the new event again. Or complete the form without a location, then create the new location in that area, then edit the event I just created and select the location.
This shouldn't be so difficult.