In that I agree, but per-member public/private/protected is a dead end.

I'd like a high level language which explores organizing all application data in a single, globally accessible nested struct and filesystem-like access rights into 'paths' of this global struct (read-only, read-write or opaque) for specific parts of the code.

Probably a bit too radical to ever become mainstream (because there's still this "global state == bad" meme - it doesn't have to be evil with proper access control - and it would radically simplify a lot of programs because you don't need to control access by passing 'secret pointers' around).