The thing most representative of this uncanny feeling is probably the Swift Wing prestige class. They are divine spellcasters who gain access to the Dragon Domain, a holy breath weapon, and, eventually, dragon wings. And you might think that this is because they worship one of D&D's established draconic deities like Bahamut or Tiamat, but you'd be wrong. You might then guess that they worship a god with some authority over or connection to dragon-kind. Nope. Nor do they have latent draconic ancestry or the tutelage of a dragon-turned-priest. The key connection here is "It's not unusual for these analogies to compare crusading gods and their clerics to elements of dragonkind."
But the thing that makes this prestige class so emblematic of the larger book as a whole is that this metaphor need not be a major part of the church's theology. In fact, "The relationship between a swift wing and the official hierarchy of her church is strained at best." It's not something they're expected to do. It's not something that makes sense for them to do. It's not even something that is logically possible for them to be able to do. But they do it anyway. These guys just happened to think that dragons are really cool, so they added "become a dragon for the glory of God" to their to-do list and somehow the ??? part of the plan worked itself out between level-ups.
Which is kind of great, you know. It may lead to a sense of there being too much dragon, but the idea that there's someone out there saying, "no, I need more dragon" charms the hell out of me. If you couldn't tell by my overly large collection of 837 roleplaying books, I am totally on board with the idea that there's no such thing as too much of a good thing, even if maybe I'm not quite as enthusiastic about dragons as this book might like.
I do wonder if maybe there was some corporate mandate going on behind the scenes, though. The "Draconic Campaigns" chapter starts with the quote "Dragons are an iconic part of the Dungeons and Dragons game, which is hardly surprising given that they have a starring role in its name" which strikes me as a weird thing to say that's half "ha, ha, we really like dragons around here" and half "they are holding my family hostage until I deliver optimum brand synergy." And the later follow-up "Dragons can be featured in encounters at any level, so why reserve them for the climax of a high-level game?" definitely strikes me as PR-speak overwhelming artistic good sense.
I don't know, 2000s-era Wizards of the Coast, maybe dragons can loom large in the imagination of the game precisely because they're usually reserved for the climax of a high-level game. Maybe something can cast a long shadow over the brand by being mysterious or awe-inspiring, in a way that's diluted by "introduc[ing] a new classification of animal . . . whose ancestry has draconic blood mixed in with that of a mundane race of animal."
Like, the Huitzil are cute. They have a good design with plenty of party mascot potential (assuming their habit of hording shiny objects is not used to annoy the players). But when you say they're "descended from the ancient coupling of dragons and birds" you have to understand that's fucking ridiculous, right? . . . Right?
Which is probably the biggest weakness of Dragon Magic as a book. It's mired in that murky area of D&D setting work where the necessities of the game drive the construction of the setting (dragon encounters at every level!) but then, that setting, once established, starts to influence the direction of the game (see: the numerous new widgets that this book gives us to play with). It never really gets ahold of what dragons are supposed to represent in fantasy fiction. They can be an allegory for greed, or a symbol of nobility, or connected to a primordial elemental power, or they could just be big fire-breathing lizards. And Dragon Magic, by its very nature of being a D&D book, can't really commit to one idea or another. So often, the still-charming mandate of "moar dragon plz" can manifest as simply putting a dragon-esque skin on an otherwise unrelated idea.
Unless, of course, you happen to enjoy the notion that once upon a time, a shapeshifted dragon fucked a perfectly ordinary bird.
Ukss Contribution: The Horde Gullet spell. Basically, it's an impromptu Bag of Holding, but it works by you swallowing a bunch of bric-a-brac and then vomiting it up at a more convenient time. It's an all-or-nothing affair, which makes it relatively useless for carrying equipment, but optimal for carrying away treasure, and that's an image that amuses me "ooh, gold! NOM! NOM! NOM!" More magic should be like that - a weird break with your normal physical intuitions that's honestly sometimes a little uncomfortable to contemplate.