- people who only enjoy reading classic literature
- Scientists and engineers who do not enjoy fiction
Explanation:
The Science Fiction stories are favored by people that are into that genre. It is a thing of personal taste, or even abilities to understand it. While some people enjoy it and are very passionate about it, even dedicate their lives to it, some just simply don't care about it. The people that have preferences in the other genres do not find it interesting, so they are not its audience, nor are the people that maybe have jobs connected with it, but still have their interests in other things. People that do not know how to read will automatically avoid a the magazine as they will not be able to figure out what is it about.
An implicit message is something that is hinted at but not directly stated by the speaker. In this case the phrase "I don't expect you to know what cool people wear" implies that the person being spoken to is not cool.
