Χριστὸς ἀνέστη! Αν επιτρέπεται --
We're talking about a situation that is, like it or not, complex. In the Antiochian archdiocese (in which I served until relatively recently), it's complicated by factors such as demographic makeup of parishes; there are predominantly Arab parishes, also parishes with a strong Slavic component (particularly in the parishes under Toledo, it seems), and of course parishes that are predominantly convert. Many of the Arab parishes that do employ Byzantine chant do so entirely from oral tradition; from what I've seen, the Mitri Murr books do not appear to (yet) have common currency here. In Slav-heavy parishes as well as Arab parishes, Byzantine chant may be used for Vespers and Orthros, but polyphonic choirs that use, say, Tchaikovsky (konzert!)have been common since at least the '60s (with one particularly notable example I'll mention in a moment). Convert parishes tend to prefer the St. Vladimir's Seminary polyphonic materials, or any number of other things, many engaging in the nonsense of "We need a vernacular American form of Orthodox sacred music and we need it yesterday!"
Another problem is relative indifference from clergy and bishops. A cradle Arab priest told me once that, from where he sat, the interest in Byzantine chant seemed to be mostly "a convert thing". At the same time, a convert priest in the Antiochian archdiocese told me that it was probably a losing battle to try to establish Byzantine chant (beyond Kazan's transcriptions and the Antiochian Village Camp hymnal) as normative at a parish of Midwestern converts, and that since he himself pretty much had Fr. Seraphim Nasser's English texts memorized, the textual differences one ran into using Papa E.'s or JMB's English settings meant that he personally didn't really want me using them either, so the choices were between Kazan and composing a new setting using Nasser's texts (an idea which Chris Holwey basically put the kibosh on). +PHILIP seems to be encouraging talent like Rassem El Massih on the one hand, but also apparently telling people in the meantime that Kazan is as far as he's willing to push for the time being. It's also worth noting that I once ran into a gentleman who told me he, as a Protestant, was the choir director at St. George in Cleveland in the '60s when +PHILIP was the pastor there; this person said that Tchaikovsky was normative for Divine Liturgy, but that he also very freely substituted Protestant anthems for various festal hymns, and that he was encouraged to do so, in the main (within some apparent limitations).
Polyphonic choirs, across the board, in Greek and Antiochian parishes, strike me as principally a move to democratize and popularize. That's certainly the case at the Antiochian parish I served up until recently, and I'm told that the Choir Federations in GOA mostly had a social function when they got started; this was what these people did for fun, they went to choir rehearsal, and as they grew up there were enough of them to assert some amount of authority. Now they're to a point where they're aging and not really replacing themselves, however; I went to a Council meeting representing my current GOA parish for the Mid-Eastern Federation a couple of Saturdays ago, and out of 100 or so parishes that were supposed to be represented, there were all of 7 or 8 people there, I think. I was also the second youngest person there at 36, with the youngest being a 17 year old high school student who runs the website for the Mid-Eastern Federation. Make of that what you will.
I have friends on both "sides", as it were, and it seems to me that communication and education are big issues. Perceiving a zero-sum game, it's difficult to have any kind of a constructive conversation without suspicion; a friend of mine who is very high-ranking in the Federation/National Forum circles told me very bluntly a few weeks ago that the people in choirs are worried that the chant people want to simply destroy what they've done, and that the chant people themselves act similarly paranoid (from where this person sits; this is not my opinion). Education is real problem, and it's a problem where there has to be a solution available in places like where I live, not just in Chicago, New York, Boston, and Pittsburgh. When I was looking for a teacher, my options were all at least a five hour drive away; it was ultimately more possible for me to spend a summer in Greece than it was for me to have access to a teacher in the States. A facet of that problem is that there are chanters who have learned what they know 100% from oral tradition and act as though notation is only for those who don't "really" know how to do it. Well, good for them, but they also act as though they have nothing to teach and wouldn't want to even if they did, that you either got it the same way they did or you didn't, and if you didn't, it's not their problem.
All of this is to say, to people on the choir "side", doubtless they see what they're doing as having been the default situation for some time now, and they see it as far too much effort to have to learn somebody else's game from somebody who may or may not want to teach them them (as they see it). The most charitable spin on the Forum's Frank Desby Byzantine chant transcription books, while certainly they look less than ideal from the standpoint of somebody trained to read the classical books (and I know, I've seen them), is that they represent the choir "side"'s attempt to translate this material into what they can understand so that they can try to take it seriously.
I'm a relatively recent newcomer to all of this, so there's no real reason to listen to me; as I've said before, είμαι μονο ένας βλάκας Αμερικανός, but from my own path through all of these issues, it seems to me that there needs to be a multitude of conversations in a multitude of places where all participants don't act like they're ready to throw down a gauntlet. I also am not sure how many on the choir "side" are aware just how much we on the chant "side" would truly be more than willing to teach whatever we know to whomever wants to learn, and do so with a smile and gratitude for the opportunity to pass it on. Our problem is that there really is an irreducible complexity to the system of Byzantine chant, it takes time to learn and to be able to do it, it's going to feel strange and awkward while you're finding your feet, and it will take a few years. Ultimately it's like learning a language, and that's really intimidating for some people. I got yelled at by somebody at my old parish for "being wrapped up in all the wrong details and having completely lost the Spirit" over some of these issues. The answer to that, it seems to me, is to do it well enough that the result justifies the effort to those who would learn.
Anyway, from where I sit, communication, education, and bridge-building, all done in love, are what is necessary. Except at my old parish of converts, I have found people to be remarkably receptive to Byzantine chant when it is offered in a spirit of cooperation and offering one's best to all and for all (seems to me I've heard that somewhere), out of expertise rather than partisanship, and maybe that's the place to start.