I'll let you in on a trade secret: when teachers write an exam, thwy do it with two important factors in mind. First, does the test fairly examine what the students learned (or ought to have learned) from that particualr section of the course? Second (and nearly as important) which topics, personalities, etc, can I stand to read about over and over and over and over in a fairly short period of time?
There's one in the pipeline at the moment. My students have, with less and less subtlety, been trying to weasel hints out of me. Do you suppose this was enough of a hint?