Earlier quoted context omitted.
There's a fourth dimension to it - remembering why the hole needs to be guarded for 10000 years. And if you imagine trying to have a conversation with a human from 10000 years ago, you'll realize how non-trivial that is - no language, culture or knowledge capture system would survive for this long intact. There is a fascinating body of research about how to solve this problem (with no definite answer). E.g. see https…
This stupidly assumes that the people that dig the hole won't be able to communicate with generations after it. The nuclear symbol is widely recognized across the planet so the only reason this would be a problem is if every one of the cultures that understands the importance of it is killed off.
Strangely it seems to be considered a problem by those who are actually working in the field.
https://www.theatlantic.com/technology/archive/2015/02/how-t...
http://www.slate.com/articles/health_and_science/green_room/...
http://www.wipp.energy.gov/picsprog/articles/wipp%20exhibit%...