This is sheer nonsense and IS ridiculous gatekeeping. Ensuring people who want to experience beauty need to put in work for it? Some people may never be able to visit these places, not everyone is so fortunate to be able to afford or have time off to travel. You might as well say they should never look at book of photos either, or they can never look at a painting without becoming an artist first. Maybe they would never gain a love of the outdoors if they had never seen some of these photos first and wanted to see more?
Now, I agree with the sentiment that there can be tourist overload on places, and that they should be managed well so they aren't destroyed. But 'digital leave no trace' is just nonsense. We should be sharing the beauty of the world, not restricting it.