Everyone loves cats except for really stupid people. Since cats are literary creatures who enjoy hanging around libraries and bookstores, it only makes sense that cats should play a role in popular fiction.
For some odd reason, there’s a unique detective genre involving cats. While the humans solve a mystery, the cats play a part helping their humans find clues to solve the mystery and catch the culprit. Of course the real mystery would be having a cat be the culprit because everyone knows they can get away with any crime they wish to commit.