That's where we'll have to disagree then I suppose - I don't believe that it is faulty design to have something unexpected happen as the result of reaching into a random hole.
I never said I minded "something unexpected". I said I minded instant death.
If every death came with all kinds of warnings then there wouldn't be any point to them at all.
Which is why I said several times the problem could be fixed with something very subtle.
KQ6 - try to go inland at the Isle of Wonder. Whether you're adequately prepared or not makes no difference, you'll be pinned into a life or death sequence far more complex than getting this key out with no warning at all.
That's not a death trap. That's the beginning of the puzzle. Heck, if you're not prepared, you can still leave!
KQ5 - Don't throw the shoe at the cat. Not only does it cause your death later, but there's also a good chance you may have to start the entire game over again if you don't have a wide variety of saves.
This one has a dead end issue AFTER the rat is eaten; I'm sure you're already aware of the evils of dead ends. But the puzzle occurs between the sudden appearance and when the cat catches the rat, so it does not qualify as instant death, or even an instant dead end. Besides, they won't appear until Graham has at least one of the two items to throw at it, though I think many people aren't aware you can throw the stick.
KQ1 - Go through the hole in the isolated area between the rivers without the mushroom, another warning-free game destroyer.
Yeah. But then, it's KQ1.
Space Quest - Dozens upon dozens of ways to die, typically with no warning at all that you're about to do something dangerous, despite it looking perfectly safe.
I know what you mean. Space Quest I desert. Enter the skull and find Orat; you have a chance to escape. Try that other little cave close by, and an unknown creature spits out your bones. I'm not a fan.
This isn't justification, I'm just stating that we're following an established pattern in adventure gaming that you shouldn't ever assume something is safe just because it appears that way.
Based on your examples, I'm still not sure you understand the specific issue I'm raising. I don't believe it occurs in the KQ games (especially the later ones) nearly as often as you think.