The Santa Monica Pier:
There are wonderful entertainment piers/boardwalks like that all over America. Galveston has one. There's one in Destin. The Jersey Shore. Ocean City, MD.
The Country Music Hall of Fame:
SUPER cool, even if you're not a country music fan. Definitely a must-see. And see the Johnny Cash museum while you're in that neck of the woods.
Caverns:
All across America and if you've seen one, you've seen 'em all. (Unless you're an avid caver.)
Same with historic homes. The only reason you'd care is if you have a specific interest in the home owner.
I can think of a number of attractions/sights they left off, most notably the Buffalo Bill Museum in Cody, WY. Also I always see these "overrated attractions" stories, and many of them have Mount Rushmore on the list - this is a bull#### lie. Mount Rushmore was amazing and breathtaking, and the history of it is fascinating. Custer SP and the Crazy Horse statue was a letdown, but Mount Rushmore was a star.
I love stories like this and always look at them, but have learned you have to take them with a grain of salt.