And there is not a single instance of a case where passively warning people away from a site has worked.

This proposal will probably, as intended, communicate that the builders want people to stay way.

But what it won't do is actually cause people to stay away.

The only way to do that is to communicate it actively to each generation.

This proposal instead wants the area forgotten.

I don't think that's true; they're just giving more weight to the worst-case scenario where future people have no historical continuity to warn them about the site.