I would respectfully suggest that the writer of the article go and enroll in an inter-denominational Christian missionary endeavor in some remote back woods in the world, and, after keeping to that call for a decade or more, serving G-d with Christians from different confessions, come back and tell us how serious this question is to them, as a Christian.
James Likoudis has written three books dealing with Eastern Orthodoxy. Still available is his book, The Divine Primacy of the Bishop of Rome, and, Modern Eastern Orthodoxy: Letters to a Greek Orthodox on the Unity of the Church.