[CJefferson]

The problem with gcc wasn't the GPL, it was the FSF leadership, particularly Stallman.

There were things people wanted to do with a good C++ compiler, like output a high-quality parse tree (which is useful for all kinds of things), which would have been easy to add to gcc, but were explictly forbidden from being merged into gcc under any circumstances.

This was just in case some closed-source person used that parse tree for non-GPL purposes.

This is why the C++ LSP (language server protocol, used in various text editors) used by basically everyone is based on clang, and there still isn't a gcc-based one.