I'd not seen Elizier's post on "0 and 1 are not probabilities" before. It was a very interesting point. The link at the end was very amusing.

However, it seems he meant "it would be more useful to define probabilities excluding 0 and 1" (which may well be true), but phrased it as if it were a statement of fact. I think this is dangerous and almost always counterproductive -- if you mean "I think you are using these words wrong" you should say that, not give the impression you mean "that statement you made with those words is false according to your interpretation of those words is false".