Why? The point, as far as I can see, is one per time zone; therefore, one in US Eastern, and one in Canadian Eastern, because DST may differ, but not one for each US state in Eastern. (I think this is accomplished from the factory.)

To me, it's just a cool tweak to be able to put my very own hometown on, but if I'm not going wild with that, any city guaranteed to be the same offset from UTC is close enough... so the 3-max seems pointless.