Perhaps because Glock is one of the most common handguns on earth. With a normal distribution of idiots, there must be plenty who have access to Glocks, unfortunately. Also, to the media, every handgun is a Glock, and every rifle is an AK15 or AR-47.
We get stories every waterfowl season about dogs who shoot their owners. Human sets his "hot" shotgun on the ground while he does something "more important". Excited doggie dances around, steps on/in trigger guard. BOOM. New doggie owner needed.