Okay, the "real" Adventure games of that ilk, that I know at all, are Adventure, Zork, and Hitchhiker's Guide to the Galaxy.
The Gabriel Knight puzzle seems like a sort of hypertrophy of the form. Sort of like one of those crosswords which can only be enjoyed by someone who already knows all the little idiosyncracies of crossword clues, it might be fun for the hardcore. There are puzzles that are almost like that in Hitchhiker, but I swear they were fun. On the other hand, the text itself was written by Doug Adams, and if you'd read the book (or seen/heard the radio show or TV series), you had a big advantage.
The connection between Adventure and RPGs is unclear--with Colossal Cave published "around 1975" according to Wikipedia, it postdates D&D. The connection I make to Sett's usage though is that the computer game is designed so that the player interfaces with an imaginary environment entirely through first-person character. The puzzles are a separate characteristic...something that also showed up in RPGs almost from the start, while D&D clearly influenced computer games such as rogue/hack and (partly through them) Temple of Apshai and Castle Wolfenstein. Some games emphasized puzzles, some combat, but the common factor in my mind is the character identification.