I'm trying to remember where I read this (Trailblazer, I think?), but one alternative is to replace the iterative attack bonus with the following:
BAB +1 through +5: a full attack action gives you one attack at your full BAB.
BAB +6 through +10: a full attack action gives you two attacks at -2/-2 to your full BAB.
BAB +11 through +15: a full attack action gives you two attacks at -1/-1 to your full BAB.
BAB +16 through +20: a full attack action gives you two attacks at your full BAB.
Given how, using the normal iterative attack rules, the third and fourth attack are at -10 and -15, they're really only good for enemies where you have almost no chance to miss them, or when their AC is so high you're just trying to roll a 20. The method listed above (as I recall the book where I read this saying) results in fighters and other full-BAB martials actually hitting more often, despite having fewer total attacks.
That's not necessarily a bad idea either.
The thing with the iterative attacks is that it looks like one of the aspects of 3e that was strongly being influenced by AD&D (both 1e and 2e) but didn't work in practice.
Consider how multiple attacks in 2e worked. A second attack came at the very end of the round after everyone else had acted (1e I think might have been similar, but there's also the massive fiddliness of segments messing things up). Then there's the 3/2 and 5/2 attack sequences, 3/2 you attack twice in one round (the first IIRC) and once in the next, and 5/2 is 3 attacks then 2 attacks. But your THAC0 isn't penalized.
So 3e comes along gets rid of the silly half attacks, and adds an attack every +5 BAB. But then there's the iterative penalties. I
think maybe the idea was that each new attack is like getting an attack at level one -- except that the enemies typically designed for CR 11 and 16 -- where the full BAB progression should be getting the 3rd and 4th attacks -- have ACs that are well above what a 1st level fighter can hit, and they didn't take that into account at all.
I've read that much of 3.0's playtesting was only up to about 6th level, and if that's the case this is another high level issue that got overlooked.
I think though I'd rather make the penalties -1/-2/-3 instead which shouldn't be a big deal. A fighter attacking four times per round at level 16 is not something that I'm going to worry about breaking the game when the casters have access to 8th level spells.
And again, for the purposes of using range, Point-Blank Shot is really bad. Sure maybe if your ray spell only has 30' range anyways, or you're a Rogue trying to get off a ranged sneak attack, but if I have a short range of 100', the last thing I want to do is get 30' away for a +1 to hit and damage.
Now I know what some people might be thinking "well, in most encounters, you can't shoot from 100' away". And you're not wrong. So it is a nice bonus if you're stuck being that close. But given the option, I'd rather not, tyvm.
I suspect they may have been taking dungeon environments into account here where short ranges tend to be the norm. And PBS is coming in first because low level characters are the ones doing the dungeon crawling.
I can honestly say, I've never understood why the iterative attack penalty existed in the first place. Especially with the existence of natural weapons and Multiattack. So a monster (or Druid) can charge and toss out a bite at full BAB and then 2 claws at -2 followed by 2 rakes, but my Fighter has to make 1 attack at full BAB, one at -5, and one at -10? With an additional -2 if I dare to use Two-Weapon Fighting? Yeah...ok.
It was to keep 3e's iterative attacks in line with the attack progression in AD&D. Remember that was 1 attack a round, then 3 every 2 rounds, then 2 a round. The iterative penalties put the expected damage per round on a similar value as the staged number of attacks in AD&D.
That and I think they might have been looking at how dual wielding in 2e stacked big penalties on the THAC0 and were being too conservative with game balance. (Which by the way mostly carried over to 3e with Two Weapon Fighting, but I'm well aware of those issues.) AD&D only put penalties and restrictions on PCs for multiple attacks but not monsters. But monsters also tended to have fewer special attacks and abilties too.
