Dude, when humans die, they decompose, leaving behind a skull and bones.

Yep. And what happens with those remains? They get buried, often with valuables - treasure! This must be a grave, let's dig it up!

Whoops, your "universal sign of danger" just attracts people.

It's highly arrogant and insulting for you to think any other culture wouldn't be capable of drawing that connection.

Oh, how lucky are we to have you in our midst, who - without any research or evidence - just happened to know much better than people who have researched this.