Remathilis
Legend
But it wasn't actually WotC. Kobold Press wrote Horde of the Dragon Queen. My theory is that Kobold Press didn't have the finalized write up on the dragonborn race when writing HotDQ and decided instead of using evil dragonborn and possibly causing confusion by conflicting with the PHB, to just use what they had and call it a half-dragon. We know that they had some issues getting up to date monster stats from WotC while playtesting, so it seems reasonable to think the same for certain races. This may have just been their way of dealing with the nature of working off an unfinalized set of rules, but of course WotC approved it, so they're fine with it.
Even though I don't care for it, I'm fine with it too for an adventure module. It's not a big deal. I would be annoyed to see them in a Monster Manual though.
Hate to burst your bubble...

As an aside, what do dragonborn call themselves, does anyone know? I would think they'd have a name in Draconic, but I don't see it. I've always disliked the name "dragonborn". Humans don't refer to themselves as "Apeborn". I could see some dragonborn calling us that.![]()
Dude, if my fore-bearers were as awesome as dragons, I'd call myself Dragonborn too!