Cognitive dissonance.
Their minds cannot reconcile "Ancient world used flatbreads" with "When I think of bread, I think of the fluffy stuff I eat that has been processed with yeast."
Since they cannot make this leap, the idea of using millet based flatbread- a very real thing in middle eastern cooking, and would have been a very real thing in ancient biblical periods, and right at home in the setting of the last supper (considering the meal was eaten at what is basically a diner, you would expect cheap and available fare. Millet is easier to produce in abundance than wheat, and would command a cheaper price at market, so millet based bread is quite likely to have been present at such a dinner)-- is something they cannot wrap their heads around.
If you want to be more exclusive, and say that you want only archaeologically supportable staples, you can instead use barley based breads- This is not strictly "Gluten Free", but it is significantly lower in gluten than is wheat based breads.
This of course, is still all in stark contrast to the ACTUAL INTENT of the ritual of communion-- which is a strictly spiritual experience, where the "Transubstantiation" that happens is a strictly spiritual one. The act of eating a more biblically accurate flatbread as opposed to a processed and mass-manufactured wheat based Eucharist wafer might convey a deeper spiritual connection with the words uttered by the Messianic Christ at the last supper, and thus be more effective for communion as a physical component to a purely spiritual ritual. This is contrary of course to the central dogmas in Catholicism, where the church states that the lay parishoners are basically too stupid to have a direct spiritual connection with the divine, and thus need the guidance and interpretation of the clergy to organize and structure their rituals. (which is amusingly, why the Eucharist wafer is the way it is-- with its own branding, uniform shape, size, texture, etc. It has more in common with a potato chip than it does actual bread-- despite the potato chip being much tastier.)
If the argument is being made about BREAD--- Seriously-- does THIS--
look anything *AT ALL* like this?
Or hell-- if we want to throw in the ethno-historical factors-- like this?
(For reference, that is what ethic Matzah looks like.)
If anything, you are better off getting Indian naan bread than getting church branded Eucharist, if you want actual accuracy in your ritual... which of course,
comes in millet varieties that are indeed gluten free.No- this is really all about Dogmatism that was established early in chruch doctrine, where the clergy interjected itself as the sole arbiter of what was or not permitted in ritualized communion, and established its own "Gold Standard" on what can be used in the ritual-- Namely, its branded, iconic Eucharist-- supplanting the actual historically accurate flatbreads that would have been at such a dinner table in the middle east of that period. It is all about church control, dogmatic adherence to internal church doctrines, and powertripping of the clergy-- AND SHIT LITTLE about any of the following things: Spiritualism concerning actually getting closer to Jesus via the ritual of communion, being historically accurate in the performance of the ritual, or understanding spiritual transubstantiation at a *SPIRITUAL* experience, and thus wholly independent of what kind of bread you choose to use, or even choose to use bread at all.
In short, The catholic church is flipping full of itself, and tripping balls. News at 11.