Well, now we’re just arguing about what is the ordinary sense of the word. I maintain that there is a sense of the word that allows the butterfly effect to make sense.
What was the cause of the the first world war? In many textbooks, it’s a small thing, really, and many historians have argued that it didn’t really “cause” the war–that there were larger issues without which the war wouldn’t have occurred. That’s the same sort of argument here.
The butterfly effect illustrates mathematical chaos–and your examples bring up an interesting question: If you start two experiments, one with A and the other with A+x, and they result in f(A)=B and f(A+x)=C, can you find any other value y close to A so that f(y)=C also?
In terms of your argument, you assert that the hurricane that was caused by the butterfly would have been caused by all sorts of other small things, too, and would have been prevented by many others. That’s easy to assert, hard to show. In fact, for some chaotic functions, you cannot, which makes the argument invalid, until you prove that this is not one of those functions.