There is so much of our country to see that I don't understand why anyone would want to leave it.
I consider myself fairly well traveled in the lower 48, and I haven't even passed through every state much less stayed and explored each one.
Uh, because our country is filled with Americans, all with a common history and similar experiences.
Let me tell you, you don't appreciate freedom till you spend time in a country that's only had it in the recent generation. Or in a country where they don't have it.
Foreign travel makes you a more rounded and better informed individual.
This, of course, excludes all-inclusive resorts and cruise ship which are merely isolated bubbles of hedonism.