Some of these are ridiculously reductive. Hadrians Wall 'a pile of bricks', the Grand Canyon 'a big hole'. Unsurprisingly people who were blown away by them actually took time to experience them (hiking, camping, rafting) rather than just have a quick look two metres from the car hoping for some kind of epiphany.
When you hike Hadrian's Wall knowing it's history, how and why it was built, the ancient stones and imagine those Roman Centurians standing for hours in such a landscape often with the biting wind and driving rain alone for hours it becomes something quite different. Plus the scenery is spectacular.
Having been to many areas of stunning natural beauty (Canada, California, NZ, Australia, Scotland, Nevada) I'm constantly depressed by the hordes of people who barely get past the car park to take a picture, say how unimpressive it is and leave to go and do some shopping. Saying that it frees up the stunning walks for us... barely a soul to be seen.
This is why Lands End is such a massive mess. Loads of people making long trips to see 'some cliffs'. Not enough excitement clearly so they build a bloody funfair there.
I remember an American couple who were miserable they hadn't seen any bears in Canada and declared it a disappointment. Turns out they never moved from the towns/cities as those were 'the attractions'