>They want to give others a learning
opportunity (this is the least likely of the three, I think.)

why would you think this? if one is to use this medium to any extent there are some very basic and easy tools one can (should?) learn, for answering questions such as "what is the meaning of the word x" or "who was person y", and in the process avoid importuning others -- you don't even have to crack a book very often to Look It Up!