Because a lot of destinations will have charging, but not nearly _every_ destination will have charging, not even the majority.And they will. Remember, as part of the presentation, the number of Destination Chargers is expected to explode as well.
Superchargers are nice, but as long as you can get to your destination (a hotel, B+B, whatever) and let the car charge while you're skiing, eating, etc, then what's the difference? Depending on where you live in MA right now, you should easily be able to make your way into a majority of NH, ME, and VT with the existing network. And once they build-out the proposed SC locations headed towards Northern Maine, between expected DC build-out and existing SC's, it's not as dire as everyone is making it out to be.
(and some of us head south for vacations, not everyone with a Tesla is going to go to NH, ME, VT)
I would be fine if Tesla had a future map with the holes filled in, they don't.