I've been saying this for years now. Adventure games were popular (relatively speaking) back in the day because they were pushing the technology. When you wanted to show off your new 386, you bought the latest King's Quest game. Even after the advent of first-person shooters, games such as Phantasmagoria and Gabriel Knight 2 came in and were the best-looking games around.
Current fans of the genre like to say that it was always all about the story and characters, because they want to feel as if adventure games are the "intelligent" genre and that they are more cultured than those adolescent FPS players. But as I've said ad nauseum, that is not the case.
There was a thread in the main forum here recently about multiplayer adventure games. Many people pooh-poohed the idea, saying that cooperative adventure games are not possible for various reasons. There was a thread elsewhere about the possibility of open-world adventure games. This was pooh-poohed as well, because adventure games simply cannot be done in an open-world environment.
That's the anti-innovative thinking that we're dealing with, and it's why the genre has been in this gross rut for over a decade. It's arguably devolved since 1999, and until the players and developers get out of this box and start innovating again, adventure games are going to remain a cute little niche casual genre.
Another thing I seem to recall Roberta or Ken mentioning in an interview that many of the things we now consider standard Adventure game traits, like the item trading and inventory were created due to limitations in the technology. It was a way to infuse interactivity in a technology that didn't allow for much direct onscreen player interaction (somewhat ironic that those features are considered by some fans of the genre as epitomizing higher levels of interactivity in games via everday objects, as opposed to "shooting/killing" in many other genres).
When technology became advanced to the 'half-life' era or even N64 action/adventures, and some RPGS, Ken was praising those as the future (and that adventure game as people knew it was going to be dead), as those kinds of games infused the kind of interactivity the Williams only dreamed about back when they started Adventure games. He believed in time those types of games would replace adventure games.
Roberta believed the important thing was creating towards some kind of 'interactive story' (she didn't really like the term 'games') utilizing latest technology, and opening up new forms of interactivity for the user. For a while there was a dream to merge and overtake Hollywood in the story telling industry. That ideal lead to things like Phantasmagoria and other interactive movie style games from Sierra (which argueably have more to do that the average FMV game). These games were like watching a movie, but essentially making the 'player' the director, controlling the direction of the movie.
Did it have poisonous snakes in it?
Well it does have snakes, and Medusa!