In Hide and Seek, the goal is to make the other player unaware of one's location. Hiding in the same place repeatedly makes it trivial for the other player to be aware of one's location, no matter how quiet you are.
Conversely, in the example with a single pillar, the goal at my table isn't to make the enemy unaware of one's location, it's to capitalize on one's ability to remain unseen and unheard long enough to make a target in the open less able to predict the timing of the inevitable attack. Successfully doing so doesn't require fooling the target or taking advantage of them being dumb, it just requires being quiet enough that that the target can't use hearing to know when the attack is coming.
You know what, I don't disagree with this, but my perspective is different. There are two parts of being hidden that benefit an unseen attacker:
- The target does not know from where the attack is going to come
- The target does not see the attacker prepare and aim
These are two different components. For me, the maximum efficiency is attained when both are present, which is why, if the rogue is hidden at an unknown location, he will always have advantage.
But if it's at a known location, he benefits from only one of these parts, and it makes it harder to be 100% efficient. He can still be, but it's still harder, hence the disadvantage on stealth.
From the target's perspective, at my table they still know that the Rogue is behind the pillar even after the successful hide check, and can act appropriately to defend themselves by taking the Dodge action, moving to cover, or moving to engage the Rogue in melee. The Rogue only gets repeated advantage on their attacks if the target chooses not to take (or is prevented from taking) any of these countermeasures.
And these are fine countermeasure, assuming that you can take them. But I like my game to be even more varied, and allow for additional countermeasures, some that take less effort for less benefit. If the player makes some effort in his roleplay and description, he might not negate the advantage, but just make it more difficult for the rogue to achieve it, that's all.
You appear to be interpreting the act of attacking from hiding as necessarily fooling the target in the some way in order to get advantage. That's cool, and definitely works within the very broad rules for hiding in 5e. But it's not the only way to envision what's happening in the fiction.
The thing is that, in fiction, no-one hides at the same place twice in a row. The spectator would think "that's weird, why do they fall for this, are they idiots ?" And, as I've said, with a stupid protagonist, it can certainly be comedy.
Those of use who approach it differently don't see fooling the target or making them unaware of the Rogue's location as a part of the fiction, so when we give the Rogue advantage we're not implying that the target was fooled or too dumb to play Hide and Seek. Accordingly, we're also not placing any less emphasis on the importance of the fiction than you are--we're simply using different fiction.
One that not flow with the usual fiction of the genre or with logic as a I see it, see above.