Who said they can’t remember where they were attacked from and allow it to occur round after round and do nothing about it? If you know the rogue keeps hiding behind the pillar, just walk around the pillar and put your sword through his gut! But when he is behind the pillar and sufficient quiet and varying the timing and height of his attacks (i.e. passed his Stealth check vs. your passive Perception), it’s going to be harder to avoid being hit by his arrow than if he were just standing out in the open.
But it's still going to be much easier than when he attacked you the first time and you did not even know he was there.
Once more, I'm not forbidding anything, I'm just ensuring that the narrative makes a bit of sense, and that, just as in real life, clever and inventive choices are rewarded, compared to simple repetition.
It only says that based on your assumptions of what’s happening in the fiction. Some of us have a different set of assumptions, which allow a rogue hiding in the same spot to make sense and not make the creatures they’re hiding from look like idiots.
And I'm sorry but that does not make any sense top me, which is probably a reason for which no one has ever put that kind of situation in any source of the genre. But of course YCMV.
Again, you’re assuming we’re all working from the same set of narrative assumptions. I agree that if you assume a successful hide check means your opponents have absolutely no idea where you could possibly be, then it would be stupid for you to be able to hide in the same spot more than once.
And that is exactly what being hidden does.
However, since certain rules (like the lightfoot halfling’s naturally stealthy) seem to indicate that it is possible to hide in the same spot more than once
I don't read that in that ability: "You can attempt to hide even when you are obscured only by a creature that is at least one size larger than you." It's just giving away more opportunity to hide, but once an opponent has seen the halfling disappear behind a companion once, and the halfling disappears again while there is no other concealement possible, there is a good chance that he will watch for the halfling exactly at the same place.
What gives you the impression that it's meant to hide in the same spot more than once ?
I find the natural conclusion to be that that isn’t an accurate narrative assumption. So I’ve adjusted my understanding of what’s happening in the fiction to account for what the rules seem to be implying. The rogue who hides behind the pillar gets the benefit of being hidden (advantage on attack rolls and attack rolls against them have disadvantage), so that benefit must come from the opponent not being able to get a clear shot at the rogue or see and read the rogue’s attack telegraphs, rather than having no idea where the rogue could possibly be.
The rules make it really simple: "When a creature can't see you, you have advantage on attack rolls against it." That's really all they say on the subject.
So, from this, a DM would be perfectly right in saying that as soon as the rogue pops out from behind the pillar (or the halfling from behind his friend), he can be seen and therefore does not have advantage. Whereas when you fire from a dark area, where you can't be seen at all even while firing, you would have advantage (which, by the way, is where the second sentence "If you are hidden — both unseen and unheard — when you make an attack, you give away your location when the attack hits or misses." comes in effect to tell you that even if you were totally unseen, you still give away your position once the attack hits or misses (and therefore after you have rolled with advantage).
But most of us are not that harsh on rogues popping out from "concealement", because we also apply the reading from the section on hiding that says "You can't hide from a creature that can see you clearly", which is a bit more forgiving. But because that is plain english, it's also much fuzzier, what does "clearly" mean.
And this is where, once more, we go back to the devs intentions about stealth: "This more than almost any other part of the game, is going to rely on the Dungeon Master."
You should not make so many assumptions about the way other people play based on very little information.
What you see is all there is, and so far nothing has shown that there is not a mechanistic following of just the RAW behind some contributors implementations, with some slapped-on justification. Which, once more, is fine if that is what you are looking for in terms of D&D.