This is not quite the right thing to take away from Saussure! In the absence of true signifieds, signifiers are "arbitrary" in the sense of the classical model, but that very thing opens up a huge number of questions about
how these relations are formed and enforced, in the absence of substantial nodes. In the absence of signifieds, there can only be, in a broad sense, enforcement, or "rules" to language games that form and disform as society changes, in a more Wittgenstein/Cavell sense.
Saussure would absolutely be on the side of questioning our use of language because the effects it has, he is probably the biggest early intellectual source for these discussions.
Saussure would laugh quite a bit at everyone's extreme defensiveness in this thread. So many people scared of losing their signifieds that never really existed in the first place. Consider precisely what everyone is so angry about, such that GP is being downvoted so much, it is a faith in a ground that is only a illusion, at the cost of discussions and progress that only aspire to help people. Sad!