That exception exists because compilers have a tendency to leave little bits of itself in code that they compile. For example, if you're compiling to a target that doesn't have a division instruction, you're going to be using a compiler-provided division routine that gets combined in with the source code. And that routine is a clear part of the compiler's source code.
The standard compiler license exception (this applies to LLVM to, e.g.) says that any such code that gets combined in with your application code doesn't count. Note that it's still a potential license violation to use that code elsewhere (say, using those routines in another compiler).
This isn't a concern for linkers because linkers don't really provide anything in the way of code, everything being provided by the compiler as a compiler or language support library. The largest code it might add to your program is probably the PLT stub code, at best a couple of instructions long.
The standard compiler license exception (this applies to LLVM to, e.g.) says that any such code that gets combined in with your application code doesn't count. Note that it's still a potential license violation to use that code elsewhere (say, using those routines in another compiler).
This isn't a concern for linkers because linkers don't really provide anything in the way of code, everything being provided by the compiler as a compiler or language support library. The largest code it might add to your program is probably the PLT stub code, at best a couple of instructions long.