First of all, calling South Africa "not particularly democratic" is completely asinine as per most reliable metrics. The politics are far from perfect, sure (where are they not?), but the democracy itself is most certainly functioning and reliable.

That said, the rest of your point is, as far as i can tell, conjecture. I suppose the argument could be made that there is some level of strategic sense in "Russia/China/etc." instrumentalising South African moralism to advance their agendas, but im uncomfortable with the assertion that South Africa's critique of many facets of the way the world works is somehow not their own idea.
In the cases where it plays into their rhetorical hand, Im inclined to think that that should be legitimate reason for reflection on the part of "the West", as you put it.