Hm. Very true, I'm afraid. Anyway, "violence achieves nothing" is a useful heuristic, and in times of extreme need the use for violence will still impose itself: the meme simply puts up a mental "barrier of potential" that makes sure you really think hard of alternatives before resorting to it.
I tend to distrust ideas whose usefulness depend on not being too compellingly expressed.
If what I actually believe is that there are usually more valuable alternatives than violence, I endorse saying that as compellingly as possible, rather than saying that violence is never valuable no more compellingly than appropriate.
I have found this most wonderful (if fairly lengthy) article, and thought you would enjoy having it brought to your attention.
It is so good, I think we should include it among the references in the "Politics is the Mind Killer" wiki page. But, before that, I submit it to you, and ask you: is there anything in this article that would warrant its exclusion from this site? I mean, besides the fact that it is about politics, and written by a notorious Social-democrat (And is that in itself grounds for exclusion?).