I am mostly with Max on this issue; sense shift and transferral happen, and there's no turning the tide. but 'decimate' is a particularly bad example for which to carry the flag. I say this for more than one reason:
1. the first recorded English usage was in the tithing sense mentioned above. (mid 16C)
2. the "punishment" sense was used mainly in historical, military contexts (i.e., not popularly) (late 16C)
3. the sense then shifted to the selection of 1 in 10 for anything (obs, rare - 17C/18C)
4. then, by transferral, it was applied to (A)the killing or destruction of one in ten and (B) destruction of a large proportion; subjection to severe loss, slaughter, or mortality (late 17C and on)
think about how decimate would have been used in (A) and (B) and how the meanings would have become blurred. 1856 J. H. Newman Callista The population is prostrated by+pestilence, and by the decimation which their riot brought upon them. what percentage do you suppose was meant here? we can't know, out of context, but it was certainly not 10%.
5. there is this odd citation from 1867: Freeman Norm. Conquest A systematic decimation of the surviving male adults. By decimation is here meant the slaying, not of one out of ten, but of nine out of ten.
[Bill, you'll need a time machine to fight this battle.]
addendum
by sheer coincidence, I am reading a book ["Enemy at the Gates: The Battle for Stalingrad" (an Inspiration for a Major Motion Picture 8).] in which is related a story of one Russian commander who, faced with mass desertions, "acted decisively to curb the epidemic. [gratuitous topic reference] Calling a general assembly... [he] berated them... moved purposefully to the long lines... and began counting.... As he reached the tenth man, he wheeled and shot him in the head." [repeats until pistol emptied, six dead]
does he use the word 'decimate'? no, but only two pages later we find this phrase: "as Russian antitank guns pummeled his armor and decimated his granadiers." [the book is ca. 1973]
final edit (I hope)
some might misapply the word "ironic" to this incidental juxtaposition. (or maybe he had a really sharp editor ; )
