That's not sufficient here. You can literally have a billion @nogc libraries, and even if there was one single GC-requiring library that many people want to use, the problem would be still there.

The only way to make this work is to ensure all of the libraries most people want to use work fine without a GC (or have @nogc alternatives that people would actually want to use). While not theoretically impossible, practically speaking, that's incredibly hard to pull off when you have a shiny GC sitting there.