Comment by pjmlp

A few points, Wirth usually always bootstraped his compilers, writing just enough Assembly for the minimal version 0 of the language and go from there.

Secondly, as we all know it isn't grammar and semantics alone that sell compilers, it is someone heavily pushing for adoption, deep pockets companies willing to do everything for adoption, or some successful product on the market that makes learning the language unavoidable when reaching for said product.

Oberon had nothing of that.

C++ had being from UNIX's birthplace, quick adoption by C compiler vendors and UNIX clones, exactly because of that. While being pushed by IBM, Microsoft and Apple on their GUI OS frameworks.

Rust as great language as it is, if it had been some university language done as someone thesis, not tied to Mozzilla, and their efforts to fix Firefox security issues with their C++ codebase, most likely would not taken off.