Earlier quoted context omitted.
There's a reply to esr by Alexandre Oliva which touches this point. I'll quote what he says: "That GCC plugin interface is not sufficiently stable for major uncoordinated developments by third-parties is just as true as that Linux's module interface is constantly changing, and complaints about its lack of stability in it are often responded with such phrases as contribute your driver and we'll even help you keep it u…
I believe he is talking about different kind of plugins. For example, suppose you are an editor and you want to syntax highlight c source code. You could then feed .c files to clang, get back a parsed ast and use that for awesome syntax highlighting. You can not do that with gcc and the fsf does explicitly not want you to be able to. Because you could then be writing a non-free editor to take advantage of and using g…
Considering that, I mostly agree with David Kastrup; it doesn't make sense for the FSF to bend its principles and help propietary software in order to get market-share. But, unfortunately, it's also affecting FOSS developers.