HI
I've reminded of an article I once saw in a Danish newspaper. The article was about organisations such as Red Cross etc. used games to further peoples' understanding or what they do.
The game may not be an adventure game pr. se but it has you dealing with all aspects of e.g. delivering food relief and such.
More connected to the topic, raised by the OP, I have to agree that I think it is essential that adventure games have plots i.e. is used to tell great stories about ourselves and our place in the world.