Inexplicable Presidential Matchbooks

At my mom's house a week ago I noticed that a book of matches sitting on the microwave had a line drawing of William McKinley on it. On the other side it had a few lines about him, like the dates for his term and birth and so forth, without any type of explanation of what he was doing on some matchbook. Like our 25th president is the kind of guy whose visage commonly turns up on household objects. When I asked my mother about it she disinterestedly stated that they were a "presidential series" and waved in the direction of the cabinet where the box they had come in was. I figured that in order to get around to McKinley they must have been running through everybody, so it was a bit surprising to find that they had selected only about seven guys who averaged out to being fairly mediocre -- or at least not well known. As best as I can remember it was Adams, Polk, Filmore, Garfield, Cleveland, McKinley, and Harding. I am assuming that these were randomly chosen, but I find the whole thing very odd. If it was some type of funny tradition to put middling Presidents on matchbooks, I would understand, but without some better justification, one can't help but be puzzled.