We can't pretend that we're in 16th century Moscow or 11th century Constantinople. The Church is not stagnant. With that said, it's not revisionism I'm advocating - if anything, those that only communion once, twice, or four times a year are the revisionists. Communing this infrequently demands extensive preparation, like a one-week fast.
Just because the Russian or Serbian church has been fasting a week before communion for three or four centuries doesn't make it right! How in the world does fasting from meat for a week, a 3-4 minute confession, then saying a few prayers, make you worthy of communion? As if anything makes you worthy! This kind of thing is "yia-yia-ology"...old women passing this kind of thing on to their kids without having any clue why the church does it, other than that's what their yia-yia taught them.
If you noticed in my original post, I don't advocate minimalist preparation. Yes, fasting is essential. Prayer is essential. But you absolutely cannot separate communion from normal life. Communion is meant to sanctify life, not separate us from it.
In terms of Eucharistic participation, until the 4th cent., the presupposition was that all baptized Christians were worthy to receive communion, and everybody would receive unless they were under penitential restriction. Just read the text of the liturgy - it presupposes that everyone present will commune. It's the saddest thing in the world when the priest brings the chalice out, and no one approaches.
After the 4th century, the above supposition is turned on its head, and the Christian was seen as unworthy to receive communion; this was especially strong in monastic circles.
I can't speak for what every single individual Christian was doing in Antioch, Moscow, or Constantinople for that matter. But what I can say is that this excessive kind of preparation is linked directly to the reasons which I gave before. It's a result of people beginning to see communion as simply a means of individual grace and sanctification instead of linking directly with corporate membership in the Church as understood in the New Testament.
This kind of thinking isn't "Schmemannite" or "modern." This line of thinking is in continuation with the tradition of the Church, the text of the liturgy, and the Holy Fathers. The abuse is abstaining from communion all year, fasting for a week and going to a 3 minute confession, declaring yourself worthy to commune, then going back to your original unworthy state 2 seconds later. This is not what Christ intended. This is not what the liturgy presupposes. Read the texts of it.
True preparation is continual Christian life. Excessive preparation leads one to spiritual pride, thinking that what they do makes them worthy, rather than simply the mercy of God. Prepare for communion - yes. Do so with spiritual pride - no.