I agree with the sediment "to each, his own" whether you find a geological wonder interesting or not! It does cause me pause when I hear the Grand Canyon described as nothing more than a River Gorge, just as those that think you can see Yellowstone in its entirety in a single day(been there done that type attitude), or Glacier Natl Park is a drive through adventure.
I have this visual of Mom and Dad getting all excited to see a Natural Wonder, the kids/teenagers riding in the back seat with their heads burried in a Video Game! Yes, they were there, yes they looked up occassionly so that they could say they saw it and they were there but not knowing a single element to what makes it a National interest.
Just my take on things...your mileage may very well differ!!