I wouldn't get too hung up on the origin of the name. In this case the origin was funny enough for WotC to talk about it, but I assure you how a book gets it's name is not the same as why a book is written. (Disclaimer -- I'm one of the authors of this book, and I had nothing to do with naming it. I am both biased in its favor and using second-hand information, though seeped in experience, so take my opinion only for what it's worth.)
If you see me in person sometime, ask me what Alien Anthology was originally going to be named and why it changed. Or, if you buy me a drink first, how Starships of the Galaxy got its name and what it almost was, due to marketing pressure. Marketing gives feedback, but it only gets used if it produces a good idea.
In "The Year of the Dragon," WotC was -going- to be looking for a number of Dragon releases. The fact that Dragon Magic draws on popular elements of the titles for popular books is marketing, not its entire reason for existing. If the people who decide what books get written, who are huge D&D fans as well as game writers, hadn't come up with an idea they liked, they wouldn't have approved this one. Instead you'd have gotten Dragon Kings, or Realms of the Draconic, or Dragonfire or soemthing. But most of the content would have been very similar, because these are the dragon-based ideas the guys who outlined the book wanted to see. And, given that we discuss dragon kings and dragons as analogies for elements of churches, we clearly didn't restrict ourselves to things with both "dragon" and "magic" in their description. We put together a solid concept, and followed it where we felt it logically went.
It's a good title. Its origin happens to be funny. That has no impact on the production value of the book or the thought and effort that went into it, which had the full cycle of ideas, outline, writing, development and editing, just like every other D&D book put out this year. The majority of people who bought it seem happy with it. Obviously if you don't need any more information about dragons, don't buy it! Just as if you had no interest in ocean adventuring, you shouldn't buy Stormwrack.
But don't think the book was less loved, thought out, or respected just because someone at marketing thought of the actual title.