On the other hand, when a statement is made about you ("what you did is wrong") you always have a chance to discuss the facts. When a statement is made about personal feelings ("I feel offended by what you did") no discussion is possible any more: I can counter your interpretation of facts, but I cannot possibly argue about your stated feelings. You won, period. This seems to me the danger of the "I language".
If you're not interested in moving forward together then I or you language doesn't really matter.