The much bigger problem comes when you can make the game unwinnable, but not actually lose right away (well, you've lost, you just don't know it yet). You merrily continue on for hours until much later you realize (if you do realize) that your mistake those many hours ago doomed you, and you need to go all the way back to a save from before then. Killing the player character right away (or at least soon) would be a much more merciful outcome than letting them blindly proceed down a path to nowhere.

I assume the dual intent of such dead ends were to make things seem more "realistic," as real-world errors are often permanent and aren't always immediately apparent, and also to extend the playtime.

Sudden brutal deaths are still a staple of many games and genres (even the new "modernized" King's Quest), but the silently-unwinnable state has happily fallen more or less totally out of fashion.

> The much bigger problem comes when you can make the game unwinnable, but not actually lose right away

Yeah, that sort of thing instilled a life-long habit of constantly saving my progress and having saves that go back many hours. I specifically blame King's Quest II for that. There was a bridge that you could only cross a handful of times and then it collapsed. If it collapsed too early in the game, you are screwed and need a save prior to crossing it unnecessarily.

In addition at the very end the bad guy casts a spell at you, and the bird flies into the way and you don't die... if you didn't save that bird 4 hours earlier you have no way to possibly know that is why you are doomed to failure in the final fight.

It felt like shitty game design at the time, and by today's standards it would be completely unacceptable to most players.

Yeah, I'd consider it a design flaw of the game, if it would reach a dead end that way. A better solution would be to turn mistakes in consequences of the story itself. I.e. not mechanically being stuck on something, but the plot taking a different turn, environment changing in different fashion and so on. I.e. reactivity of the game should reflect those choices and mistakes in more organic fashion. Even better, the game could provide alternative solutions to problems, allowing to work around previous missteps even at later stages (but may be requiring more effort and time).

That feature was a nice reprieve after playing the Sierra-designed games. Though sometimes the abrupt endings in the Sierra games had their point; for example, forgetting to secure your weapon before taking an inmate into jail would result in a game-over scene in Police Quest 1. Not sure how that could be resolved the LucasFilm way.

I never found any other ways to kill him, but I certainly tried.

From reasonable abrupt endings, the most hilarious one was in the Neverhood: https://www.youtube.com/watch?v=S4MARAsx1Vo

"No... that's not what happened."

Then you start the scene over.

Stupid cleaning robots....