I think there are some folks who want that precedent to be set and that's why they won't even consider including an optional rule for half the community.
GWF
is an optional rule.
It's about whether, in the heat of the game, people are questioning the narrative.
<snip>
A miss should be a miss, and a hit should be a hit.
."a convincing answer" may be harder to generate than some might think.
These questions, and what counts as a convincing answer, are based very heavily on past gaming experience, though.
For instance, we stick with hit point rules even though some players might question "How is my guy alive and unhindered when he's been hit by 10 crossbow bolts?" or "How does my guy know that he can't die if he jumps over a 50' cliff?"
Conversely, at least in my experience, once players come to think of hit points as ablative fate points; and once they think of attack rolls as simply allocating the ablation of those points; then none of these issues - falling, archery, damage-on-a-miss - causes any confusion at the table.
Once you've accepted you have to narrate a miss on the armored knight differently than a miss on the agile rogue, you're already at that point where the mechanics aren't feeding you the results.
You tell me that the fighter doing damage is missing plenty but now that the person goes down, its no longer a miss.
I agree with TwoSix. The "kill via damage dealt on a miss" seems to me no different from normal hit point narration: the fighter who rolls a "critical hit" against the dragon at full hit points just delivers a graze (it still has the bulk of its hp left), but the fighter who rolls minimum damage against the dragon with 1 hp left delivers a critical hit.
When a mechanic tells you that rolling a 5 in one round represents a miss where you are forcing a character into exerting himself, but the 4 on the next roll against the same opponent represents a lethal strike, the narration is dissassociated from the actual mechanics.
I prefer the dice rolls and the mechanics to have some relationship to the narration
Well, they do have
some relationship; and the degree of "dissociation" is no different from that already present in a system with "critical hits" that are very often not critical, and "minimum damage" that can well be fatal, and (generalising from the above) damage rolls which have no meaning to be ascertained independently of the context in which they're applied.
Is a d20 roll of 3 a good or bad swing? Well, for an 11th level fighter fighting a goblin, 3 + 5 (STR) +4 (prot) + 1 (magic) is a hit vs AC 13. For a 1st level fighter fighting the same gobling, 3 + 4(STR) +2 (prof) = 9 which is miss vs AC 13. So the d20 roll has some relationship to the narration, but that relationship can't be determined independently of the applicable bonuses and the broader mechanical context.
Damage rolls are similar (as the earlier part of this post shows).
There are plenty of spells where the effects are entirely non-random, many of which are a much closer match to what might be obtained by a Called Shot than ones which reduce a random number of hit points.
In addition to these sorts of spells, there is the fact that many spells do auto-damage which NPCs/monsters have no chance of surviving (eg a Next fireball does minimum 3 hp damage, which auto-kills a goblin or kobold; and most fireballs will do a minimum 4 hp damage, which auto-kills a human commoner).
that doesn't mean it's dissociated, just abstract & over-the-top.
No disagreement that it's over-the-top ("gonzo" is my normal way of characterising this). The fighter in question is a dreadnought fighter who relentlessly wears down their foes.
I don't see it as any more over-the-top then the D&D mage who can drop fireballs and conjure lightning bolts that auto-kill ordinary soldiers by the bucket-load.