I could not agree more Cino, I believe that the core reason and purpose of folks of having a dialogue circles around the domain of proving each other right or wrong, there are very limited few like the sand grains on the sea shore who have a genuine intention of learning and finding the best path towards the Creator.
I also appreciate your concerns to leave other Messiah's alone in the sense that folks should always be respectful and courteous about other people doctrines and faith, because it matters!
What we understand from history and our current times is all the great Messiah who lived their lives and carry significant weightage in turning the course of mankind had one and same purpose, that is rejuvenating the link between the created to the Creator, and they all come from one single source, the Creator.
So if the purpose of having a constructive dialogue is to find out the best way to connect to the Creator, it makes alot of sense, otherwise the dialogue becomes meaningless, as we all fall into the whirlpool of proving each other right or wrong with no outcome.