What's in a bagel?
You're missing the point, Joe. The problem with the bagel isn't what's in it; it's what using it means, in the context of its use. As a field expedient, it's bread. As the centerpiece of Sunday mass, it's an expression of-- well, maybe not frivolity, but definitely a reaction against solemnity.
Scrupulosity about the elements backfires easily against hosts. "Angelic fish food wafers" (to quote Fr. Capon) don't register to most people as bread. And in many respects they exist precisely because the reality of genuine bread offends the scrupulous. I once obtained genuine unleavened bread for a Catholic priests: matzos. Do you know what happens when you break a matzo? It explodes with crumbs, followed immediately by the more excessively pious members of the altar guild. But that is what real unleavened bread does.
Breaking bread with a rice cracker is as much of a scandal to some as using a bagel, when it comes to the substance.