I'm sure it's a very small minority, who probably have nostalgic memories of Sierra from the 80's and 90's, but I have seen enough people decry the "casualization" of adventure games to assume that just because I don't like something, that everybody else must hate it as well.

I usually know them simply as walking deads or dead ends.
And they're certainly not limited to Sierra games. Kyrandia 1 (and possibly 2 and 3) had them, Lure of the Temptress had them. While later LucasArts games made it a design point not to have them, Maniac Mansion, for example, had them.

I don't think you'd find anyone who'd think they're a GOOD thing. They can usually be avoided through well-thought out design. If you have an item early in the game that will be needed later in the game to progress, just include a puzzle early in the game that will require that same item.
You could even foreshadow the later use by making it a similar situation, just easier.

That thing is useless! :P So it means you can lay down anywhere, which means you are likely to get attacked in the middle of the night. In order to be safe you need to find a room or something, which 99% of the time has a bed or straw in it anyway.

IMO you can still consider something as bad design, even if there might be a handful of people who like it. Otherwise you couldn't talk constructively about good design at all, because "anything goes". I'm a fan of point-and-click adventures since Maniac Mansion and the first Larry game, but I don't know anyone who'd regard removing these situations from adventure games as "casualization", and if I knew someone who did, I couldn't relate to their opinion at all, not because it's different from mine, but because it doesn't make any sense to me. I understand why people like rogue-likes, even if they're not really for me, in most cases. But in these games, at least every playthrough can be a little different. Most point-and-click adventures are much too rigid and linear to make replaying them due to failure fun. For a majority of potential customers, that is, and I'm sure the devs don't want their games to be that niche that they only cater to this very very small (if existent at all) minority of "hardcore" adventure gamers who enjoy failing in their first playthrough.

Of course you can call things bad design when analyzing a particular game. What I protest is calling a mechanic bad design, and apply it as a blanket statement.

The Tomb Raider reboot was so full of cutscenes, QTEs, and scripted sequences that I got mad at the lack of interactivity and dropped it just an hour in. Persona 4 takes two and a half hours to get to its first battle, but I loved the game and the way it tried to set up all the characters and its world before getting to the crazy stuff. I can't say that a light on gameplay, slow and scripted start to set the mood and characters is either bad or good design, I can just comment on how well it worked in each game.

Which is why I said you do have a point; I just can't see any (linear) game applying this particular 'mechanic' here in an enjoyable way, until I'm proven otherwise, and so I see no problem with calling it bad design, for the time being.

Btw, the "casualization" of removing death and unwinnable states from point-and-click adventures was introduced by LucasArts in the early 90's. ;)

And Tomb Raider gets much better after the first hour. I loved it, despite its bad design decisions. XD

I am mostly OK with that but only if the game clearly tells you it is important quest item.
Then it is only players fault for not being dumb.
It can still ruin whole playthrough so I think it is better if they avoid doing it.

On the other hand if the item is in no way amrked then it is beyond stupid and such design needs to be wiped from the face of earth with fire.

Yes, I think you should campaign governments to pass laws preventing developers releasing games with such things. including games released 20 years ago.
Really?
Its not great design, but sometimes happen, especially in big open world games.

What's described in the OP is not really a gameplay mechanic tho, more like ... Lack of it. And you can actually design an adventure game in such a way that every location which contains an item you'll need later on is available throughout the entire game, so yes, I'd say combination of barring player from previous locations and need to collect certain items at said location is a very bad design, even if these things aren't when looked at separately.

In all the other genres you've mentioned, dying is a result of lack of skill. In adventure games, dying is a result of clicking the wrong pixel. Since you can save/reload even in older adventure games, dying is completely meaningless as all it means is that you won't click the pixel next time. There's no skill or improvement involved whatsoever, altho it can be somewhat entertaining. In adventure games, you get stuck at not being able to solve puzzles. That's the challenge in those games, that's what you need skill for and that's the barrier, pointless death scenes notwithstanding.

There's a difference between "challenging" and "lol, we just wasted your time". A puzzle isn't made more challenging by requiring an item one would have to be clairvoyant to know about beforhand. And having to start over is just a waste of time, not a show of skills. It's like in some other game if there is no checkpoint before a boss fight, and I have to play through the entire level again if I die. The boss fight is not harder because of that. The boss fight is exactly the same. It's just that I have to waste a lot of time to try it again.

I like point & click games precisely because the are not like The Witcher or some other RPG or action game. After playing action games, FPS, or some other thing like that I often want to play something relaxing for a change of pace- something where I can take my time, and just enjoy it. That doesn't mean the puzzles are not challenging. It just means I can actually solve them without reloading the game X times.

It really annoys me when people point at poor desing, call it a "challenge" rather than what it really is, and wear the fact that they wasted hours if not days of their life overcoming that instead of playing a better game like some twisted badge of honor. It gives developers an excuse for their shortcomings they should not have.

Anything that artificially interrupts progress is a fundamental design flaw IMO but where to draw the line from a less subjective (but not entirely objective either given it's a medium to enjoy) perspective would be interesting to discuss.

I've been waiting for someone with that opinion, to prove that they exist. Thank you for showing up! :D

So are you saying the adventure games with mediocre story that you list would have been more fun to you if they had tried to kill your character at every possible occasion or told you near the ending that you can't win them anymore because you forgot to pick up an item in the first chapter? Would that have saved them? From what I hear "Kingdom: The Far Reaches" might be a more challenging adventure game then. Mediocre in every other regard, but you can die a lot! ;)

To me that sounds kind of absurd, like saying if an action game can't deliver on the action, at least it should have lots of puzzles and dialogue ...

But it isn't a mechanic. It is a faulty methodology. No game designer sat about planning the game and decided intentionally "Okay, in THIS part, I'll put a walking dead that nobody can pass if they didn't do whatever near the start of the game". They always come about unintentionally.

(Also, the Dig had no challenge :D? I agree it had a blander story than most LucasArts games, but that was compounded by absurd puzzles that were unnecessarily difficult).

Here's another interesting question:

If the game provides a clear warning before the point of no return (complete with a message like "Are you forgetting something?"), is it still a serious design issue?

(The game I am thinking of is Wizardry 4, which actually provides a clear warning before you enter the Cosmic Cube. Interestingly, in the Cosmic Cube, there's one encounter where the enemies' battle cry outright tells you the solution to the puzzle needed to get the item you missed. The "Are you forgetting something?" quote appears many times in Wizardry 4, including once after the missed item (which you can't get until later) and once when the game warns you of the point of no return. Also, I note that clues in Wizardry 4 are usually very cryptic; this warning is a blatant exception to that rule.)