The disconnect in your post (and in the rules!) is that one melee attack roll represents multiple swings, parries, thrusts, and reversals, while one ranged attack roll is (almost always) one unit of ammo expenditure.
Why do you say that? I haven't assumed that at all. If you break it down, this was more inherently true in 2nd Ed. than it was in 3E, because the standard round was 60 seconds, as opposed to 6 seconds.
Back in 2nd Ed., a fighter might have 2 attacks a round....maybe 3, if they are fighting with two weapons. And that's for a lvl 20 fighter. I think the absolute best was a lvl 20 fighter, with the two-weapon fighting proficiencies/skills, and weapon specialization in the weapon they were fighting with. And it had to be paired weapons....since I think they could only specialize in one weapon. So if you were specialized in shortsword, and had two of them, and were lvl 20, you had 5/2 attack for each weapon, or 5 in total for the two weapons (3 with your main hand, and 2 with your second). Most characters had far less.
So, at most, if taken literally, a lvl 20 fighter in 2nd Ed. could have 5 attacks in 60 seconds....or one every 12 seconds. In a fencing bout, 12 seconds is an *eternity*. And for most characters, they only had 1-2 attacks per round. A rogue with two weapons would be 2 attacks in a round, and a cleric or mage would be 1 attack in a round. One action in 60 seconds. That just doesn't make sense....hence, it was interpreted that they're not just standing there for 55 seconds twiddling their thumbs, and then taking 5 seconds to take an action. It was stated that they were moving back and forth, circling, feinting, attacking and parrying etc. and all this was resolved by the one attack roll. It was abstracted.
3E was abstract with respect to hp, but I'm not so sure it was with actions. The round was much shorter. In 3E, a lvl 20 fighter would have 4 actions, minimum, unless he was moving around more than 5'. If he had two weapons and also the feat chain leading to greater numbers of attacks with his second weapon, he could get up to 4 extra attacks, for a total of 8 in a round. So, 4 actions in a round could be 1 action every 1.5 seconds......or as much as 1 action every 0.75 seconds. This is far closer to realistic than 2nd Ed. was, so I'm not convinced that melee attacks are abstracted whereas ranged attacks are not.
Thinking back to fencing, and what my the master at our salon had mentioned, fencers tend to be quicker than those who fight with "real" blades. It's a different mentality. He commented about an argument/dispute that arose between a fencer and a sword fighter about which discipline was better. The fencer won in seconds...but only because he was working under a different set of parameters than someone using live blades would be used to. He was just looking for a touch. Fencing tends to be more direct, with fewer flourishes than are used in sword fighting. It likely may have been a different story if live blades were being used. The point being that fencing is faster. Some hits are scored so quickly that the eye doesn't even register it. It's all counted via the sound of hits, or the signal going off to indicate a point scored. So though I'm convinced that there may be more than 1 attack a second occurring at certain points of a fencing bout, it's averaged out, because there are also spans where it's all footwork and manouvering, where there are no actual attacks with the sword taking place. And in a battle with live blades, it might be a little slower, because even more work has to be put into defense.
So, with two experienced fighters, each getting 4 attacks per 6 seconds, that's a total of 8 exchanges in 6 seconds, or one every 0.75 seconds.
If you break it down that way, I'm not so sure that the # of actions in melee are nearly as abstract as it was in 2E.
Banshee