The truth is that, like Tetris, everyone plays Doom at some point in their life. Doom has been so ubiquitous for so many years that you practically have to have been locked in Kimmy Schmidt's bunker not to inadvertently wind up with a copy of Doom on your hard drive.
The Columbine shooters, Harris and Klebold, who killed 12 students and one teacher before committing suicide in 1999, supposedly rehearsed their attack by playing Doom. Some Columbine victims even sued ID Software and GT Interactive (Doom's publisher), but they were ultimately unsuccessful.
Bad things, sadly, will continue to happen. And we won't always be able to explain why these things happen. For the past 23 years, Doom has served as an all-purpose, easy-to-point-at scapegoat, a convenient, media-friendly way to explain what we can't otherwise explain to one another.