You said it was a mistake to move him because it hurt the pass rush. The move didn't hurt the pass rush. In fact, it probably helped the pass rush, at least when he was healthy. You said it was a mistake to move him because he isn't very good at LB. I agreed that there are other aspects of the LB position besides the pass rush that he isn't good at. All that nonsense about the 4-3 defense had nothing to do with that particular line of reasoning. So what if his best position is 4-3 DE? That doesn't mean that he should play DE in a 3-4. As you said, they are different defenses with different responsibilities.
You took the conversation sideways, and I still don't get why.