Oh, okay. That makes sense if we take that sentence out of context and treat its wording literally, so now I understand what your GP was saying. However, the

Oh, okay. That makes sense if we take that sentence out of context and treat its wording literally, so now I understand what your GP was saying. However, the real meaning of that sentence as used in your GGP is that these so-called "ethical" choices you might make aren't actually ethical if they don't have any impact on the world. That is, leaving a company because it performs unethical behavior does not stop the unethical behavior from continuing, and so your leaving is merely an ethically neutral action (in fact, by remaining silent, you're enabling further unethical behavior).