Because that was the beginning of the adventure game era where there was no concept of game design and ensuring that the games made logical sense, hence the birth of “moon logic”, thanks Roberta. These games were also made to be obtuse because games were very expensive back then and making obscure logic was an incentive to make things more “worth” it, often intending to make the game last months of play time to solve their “logic” puzzles and you had to be in tune with the game designer to get them.

Not to mention that due to intention or lack of game design, these games were notorious for allowing you to put yourself into a unwinnable state with no way to correct it, things like Space Quest with the alien kiss of death that won’t trigger until the very end of the game or that Kings Quest game where you had one shot to throw a boot at a cat or you’d be dead man walking.

Not being able to finish these games wasn’t even unusual back then without the help of friends or BBS. Heck I had games adventure games I bought from that era that I never finished until the got re-released on Steam.