Don't have a need for them. I want to see the ocean? I have two coasts that span about 1,000 miles on each side of the country. I want beaches? We got that too. I want to go mountain climbing? Got it, with three different ranges. I want to see exotic geological formations, gorgeous scenery, and cool wildlife? I'll head to yellowstone. I want to see the desert? I'll head to Arizona.
Ect. ect. ect.
Face it. Outside of "cultural stuff", most of which ohhh...95% of americans could give a rats ass about

the US already has. We can just hop in a car and drive basically a max of 20 hours to get to it.
Everybody speaks English(Unless you go to Miami) I don't get charged $4 a minute to make a phone call to my relatives, and I don't have to pay for $1000 in legal documents(for a family of 4) to get there. That doesn't even include the hastle and price of flying across the Atlantic, the problems of getting around the other countries ect. ect. ect.
For a majority of Americans, and their nominal 2 weeks of paid vacation, international vacations are unrealistic. When you are in the middle class bracket, which a majority of americans are in, they are pretty much unobtainable.