So, the argument in the opening post mostly comes down to “you can’t just walk right in front of a creature after taking the hide action without being spotted because passive perception exists,” but that doesn’t actually fix the problem because a high enough roll on the stealth check can still exceed the passive perceptions of any enemies present. Consider a 1st level rogue with 16 dexterity and stealth expertise. A 15 is required for a successful stealth check, so at bare minimum monsters would need a passive perception of 15 to see the rogue (10 if the DM decides to arbitrarily give them advantage on the check, if they feel like making the rogue player feel cheated, I guess.) There’s also nothing in the RAW stopping the rogue from repeatedly taking the Hide action in a safe location until they roll a natural 20, which means it actually takes a 27 passive perception to find this rogue (or 22 with the arbitrary “screw-you” advantage.) And that’s at 1st level. It only gets more absurd from there.
Now, I do understand the complaint that, if a hidden character can’t remain hidden outside cover or obscuration, it’s impossible to sneak attack in melee or to move from one hiding spot to another in combat. This is why, in the 2014 rules, the DM decides when circumstances are appropriate for hiding and can rule that an enemy is sufficiently distracted not to notice a hidden character who isn’t obscured or behind cover. More importantly, if they wanted to provide a solution to this “problem” that wasn’t reliant on DM fiat, they could have done so without also enabling hidden characters to stand out in the open completely unseen for as long as they want with a high enough stealth check. They could easily have said in the rules for the hide action that ending your turn without sufficient cover or concealment to take the hide action ends the “invisible” condition. That alone would have fixed the problem.
Also, can we please stop saying that calling the condition “hidden” instead of “invisible” would have fixed the problem? Obviously I can’t speak for everyone who dislikes these stealth rules, but I know I’m far from the only one who has very clearly stated that the issue I take is with the mechanics of the condition and the features that grant it. If they made any of a number of changes I have suggested without changing the name of the condition, that would be perfectly fine. If they changed the name of the condition and left everything else the same, I would have exactly the same complaints about it that I do now. It’s frankly mildly offensive that defenders of the new stealth rules keep saying “this wouldn’t have even been a problem if they had just called the condition ‘unseen’ or something” because it shows that they’re not really listening to what critics of the stealth rules are actually saying. It’s one thing to disagree with our critiques; that’s fine and a normal part of these sorts of rules discussions. But to completely ignore our critiques and dismiss us as just not being able to look past the name of the condition is extremely rude. Please try to engage with our actual critiques instead of continuing to ignore them in favor of this extremely stupid strawman.