This is actually the very heart of the problem. It's not 'damage on a miss'; it's damage on a hit. How do we know whether it was a hit or miss? Because by definition, a hit is defined as "Solid enough of a blow to do damage." That's the D&D definition of a hit. If you are seeing damage, you are never seeing a miss. There is not need to invent a category for 'lesser hit' and then say, 'oh that was always a miss, now I'm going to call it damage on a miss' as if there was some narration of damage that wasn't considered in the system until 'damage on a miss' came along.
Where people get confused is they understand that hit abstractly include some sort of measurement of luck, skill, destiny, and so forth as well as the capacity to sustain physical punishment. While that is true, it is also true that under D&D's model, all hits have always caused physical damage. Gygax defined hits as doing damage; even Mearls has asserted this traditional definition. The way to really see what hit points are is it think about a relatively unskilled fighter with 5 hit points, and a quite skilled one with 30 hit points. For the low skill combatant, all 5 of his hit points represent the ability to absorb physical damage. So if someone swings a sword at him and does 5 damage, the low skill combatant has little ability to evade this attack, he takes the full blow and possibly dies. For the high skill combatant, he may still have roughly 5 hit points of ability to absorb physical damage, but he now has 25 entirely abstract hit points representing his ability to turn aside blows, block blows with his shield, or dodge aside at the last moment so that he only catches part of the blow. When the high skill combatant is attacked by a sword and takes 5 damage, he loses physical health and abstract ability proportionally, so that he loses perhaps just 1 hit point of physical health and 4 hit points of abstract metaphysical health. The fighter took a 5 point hit, but he received the damage that the lower level combatant would have received on a 1 point hit. The rest was evaded. There is never a case however where he is hit by a blow that damages only his metaphysical health. All hits do at least some physical damage. That's the way it has always worked.
So, now that we understand how a hit has been defined, what is damage on a miss?
The answer is nothing. It's a contradiction in terms. It's an oxymoron. A miss is defined not by the fact that it whiffed, but by the fact it did no damage
People trying to justify 'damage on a miss' do so through several impossibilities before breakfast. The first is requiring us to try to concretely visualize what the abstract portion of a character's hit points are. So you'll here suggestions like, "The blow misses (maybe even whiffs), but it tires the opponent out.' But while vigor and fatigue might sound like reasonably good components of the abstract metaphysical health of character, in point of fact D&D has never modeled fatigue through the hit point mechanic. First editions fatigue rules weren't entirely coherent, but the most prominent example I can think of models fatigue as temporary level drain. Third edition coherently defines it as a condition. Neither generally applies to any kind of ordinary exertion, and really, if it is fatiguing hits we are trying to model, why not have them apply a debuff instead of doing damage? If you try to model hit points as fatigue, you end up with absurdities - why don't you lose hit points for attacking an opponent, running, climbing stairs, dancing, etc. Shouldn't any aerobic exercise do at least as much hit point damage as spending six seconds dodging and parrying if all we are modeling is fatigue?
The second problem is that they ask AC to be abstract, when in fact AC is not entirely abstract but can often be broken down into components even in 1e. We don't usually worry in D&D about why an attacked missed, and we leave that to free narration. But there are times when the only narration that makes sense in the system is one or the other, because the AC of the target is clearly entirely one thing or the other and not some mixture. In the 3e stat block, the break down of what makes up AC is done formally, and it even tries to define special conditions - 'touch' and 'flat-footed' - when it narratively makes sense that one component of AC is missing. In D&D it is possible, to know if an attack whiffed, was dodged, or block, or glanced off armor by working backward from the more abstract AC to its less abstract components. But what about a case were every attack that wasn't a hit, we know to be an attack that whiffed. In that case we lose the ability to narrate this consistent with the rest of the fiction created by the game mechanics.
One of the reason that we have to each hit connect with flesh is that hits in game trigger process consequences - energy drain, poison, bonus fire damage, paralyzation, etc. If it is 'damage on a miss', and we don't know whether this means a whiff or contact, we don't know whether or not to trigger the consequences. If we treat this as fortune in the middle and hold off narration further, the logic of the save system breaks down. If you were 'damaged on a miss', but we resolve this a Stormbringer whiffing because your soul wasn't sucked out, why did you need to make a Fortitude based body save instead of a Relfex based evasion save? Surely if it whiffed (but still did damage!) and that's the reason your draining attack failed, a Reflex save is the appropriate color of what happened and not Fortitude. And so forth.
In short, within in the existing framework of D&D, accepting 'damage on a miss' involves accepting that the mechanics are meaningless within the fiction. If you always believed the mechanics were meaningless within the fiction, that's probably an easy thing to do. But its quite clear that the writers that created the mechanics didn't feel they were meaningless within the fiction, and that many people use them as process simulation/physics to inform the narration and always have.
And frankly, if you think that is 'Pervy', get the heck of my game system and go play some Forge approved rules set. And no, 'X system plays better as process/simulation' isn't a retort. I like D&D they way it always played. I don't want it more or less abstract. It's a sweet spot for me. If it isn't a sweet spot for you sorry, but this is mine.
