The night sky as seen from one location 50 years ago and tonight. See this site for more about light pollution and its effects.

Obviousy if you like bright lights and want to be able to see nearby things well day and night, you won't care about dark night skies.

But if you have ever been under a really dark night sky and been absolutely in awe of the thousands of visible stars and the beauty of the night sky, you will change your opinion. And of course for astornomers, the darker the night sky, the further you can see and the dimmer the objects you can see.

If you haven't done it yet, click on the little picture of Saturn in your viewer's toolbar. Unclick all layers and pan around and zoom in. After exploring on your own, turn one one or two layers at a time and explore the placemarks. I think you may have a hard time leaving quickly once you begin to explore.