For me, one of the more surprising features of the D20/4e derivation of Dungeons & Dragons was the introduction of a race of dragon men as a default player character choice. Although I was reasonably familiar with D20/3e, I was indifferent to the debut of the "dragon born" in Races of the Dragon, and unaware that they had achieved any degree of popularity. Having read a good deal of Dragonlance as a teenager, I was familiar with the concept of dragon men in the form of draconians (evil foot soldiers of the Dragon High Lords, and surrogate orcs). Still, I was somewhat surprised to find heroic versions of them in the Player's Handbook.
I should say that I do not think that dragon men are a bad idea, quite the opposite in fact; I think that they are in good company. Traditional adventure games abound with human-animal hybrids: lizard men, snake men, hyena men, frog men, and so on. Such monsters have ancient mythological and literary precedents, which are often directly borrowed. The hybridisation of man and beast as a signifier of the fantastic has a long pedigree. Strictly speaking, dragon men stand slightly apart from this as a combination of man and imaginary beast, but this does not detract from the shared root. However, "beast men" are typically presented as an "other", outside of society and conventional experience, sometimes under a curse, and almost always dangerous for ordinary men to interact with.
Nonetheless, the appropriation and normalisation of the other is not an entirely new or modern phenomonen. A strange heritage is almost axiomatic of the heroic archetype, helping to explain their mighty deeds and emphasise their special nature, whether descended from deities, demons, or conceived through enchantment. Indeed, the traditional "demi human" races are arguably attractive because of their combination of familiar and alien qualities; elf, dwarf, gnome, halfling, half-elf, and half-orc. Presenting them as more than humans in exotic garb has been the stated aim of many a would be innovator, but the very elusiveness of that goal should be a clue that their primary function is as a foil for human experience.
I do not imagine myself alone in concluding that characters like Tanis Half-Elven and Drizzt Do'Urden are the true forerunners of the dragon born as a player character choice, rather than the more obvious draconian analogue. As a "fragmented and declining warrior race of honourable mercenaries" they have a stoic "last of their kind" quality, and are effectively constructed as an entire society of powerful and exotic loners. Whilst the more Elricesque themes have been reserved for the tieflings, it does seem to me that the D20/4e dragon born are a familiar trope in a new skin.
Of course, I wrote as much of the draconians by comparing them to orcs, and in doing so am saying little more than "there is nothing new under the sun", but that is only tangential to my purpose. One of the things I find most attractive about traditional adventure games is the simplicity of the basic rule structure and consequent ease with which additional content can be introduced. Whilst some might understandably balk at the idea of using a concept so closely associated with D20/4e as dragon men, I view them as no less appropriate for swords & sorcery adventure than more conventional human monster hybrids. Indeed, I found the prospect of adventurers encountering dragon men so appealing that I decided to write them up and make them available here.
Whilst I was not particularly interested in the "noble warrior race" angle, I did rather like the idea of dragon men as born for war. I wanted them to be similar in power level to hobgoblins and gnolls, so decided to give dragon men two hit dice and make any wings vestigial. A minor breath weapon seemed the simplest way of conveying a "draconic" aspect in combat without making them overpowering, and an immunity to magical fear a good way to make them more reliable. I like monster background to be relatively open, ideally conveying a few different alternatives for the reader to develop. As presented above, I think there are two or three directions suggested, but I would expect more imaginative souls to think of many more that would be equally or more appropriate.