For that matter, across the globe - hyping is the name of the game. Economics or money grubbing. That being said, not every attraction is for everyone. The Empire State Building would stand for me as overhyped. Outside of it being an interesting building architecturally there’s no other reason to visit it; yet it is mobbed every day by tourists.
Under-hyped - The Allagash Wilderness Area in Maine. This makes me happy. I like the 110 miles of peaceful canoeing.