There seems to be confusion about the difference between heresy and being good, nice, and pious people. Many think that if we love someone or some people, then we will approve what they say or do. This is not the case with the saints (here, those involved with heretical issues and schisms) of the Orthodox Church or even Christ Himself. Did they not love? Did they not want to see unity prevail and people living in peace.
As far as the text mentioned, i.e. the declaration from Mount Athos, it can't be considered all that old. Something from 1994 cannot be considered "old" when the monophysite issue goes back to the first centuries of the Church. Because monastics, or anyone for that matter, express concern over an issue does not mean that they are trying to run the Church. The Church's history witnesses to many monastics taking a stand for the Faith against heretical beliefs, and vice versa (some notable ones being St. Maximus the Confessor, St. Theodore the Studite, St. Gregory Palamas, etc). Laity, clergy, and monastics alike can be wrong. All Orthodox Christians have the right to show interest and be involved in matters of the faith. You do not see these monastics holding their own councils and the like, going against the Ecumenical Councils and the Fathers' teachings. (That has happened in the past with priests and bishops, even patriarchs. Are we to say it's okay because they're the hierarchy.) It has happened much more frequently that bishops forget the Church is not a boat for them to steer where they like. The Holy Spirit controls it and we try to stay aboard and not go our own direction.
We should look towards the Ecumenical Councils' and saints' teachings on theological issues instead of saying, "I think so and so are great people…" or "I don't really understand the issue, so I don't consider them heretics." Calling something heresy, schism, outside the Church, etc. does not mean you don't love them and they are in total delusion. We should witness to others of the truth of Orthodoxy exactly because we love; this is the example the saints gave us. It is out of love for others and for God that so many have stood up for, tried to "preserve," and even martyred for the truth.