I would have posted this as a poll, but I wanted to read some cogent discussion. My students say that the games consist of "random puzzles without much of a unifying plot". From just looking at the game descriptions and playing similar games such as 3 in 3, 7th Guest, and 11th Hour, I find this whole genre too tedious and boring to play all the way through. It just feels like homework to me.
My cousins were crazy about 7th Guest, and I remember a few classmates who liked puzzle games. Since the mid-1990s, though, and especially since I started my LJ, I haven't come across anyone who professed to liking them. Anyone?