let us as liguaphiles encourage the use of etymologically accurate words

My point precisely. According to one resource, the "etymologically accurate" definition of "nice" is "[O.Fr. nice, foolish, simple - L. nescius ignorant - ne, not, scire, to know]" So we should, apparently, be encouraging people to use the etymologically accurate definition, and ignore the reality that the word's definition has shifted. King Canute made a valid point, one applicable to the tides of change in both water and language. If, as you say, we don't need a specialist word for killing one in ten, what's wrong with accepting the currently popular meaning of decimate? The shift in its meaning is dramatic, but so is the shift in the meaning of "nice", and no one is arguing that we try to turn back that tide.