The shooter has been in development for more than five years — id's John Carmack originally announced it at QuakeCon 2007 — but Pete Hines, vice president of marketing and public relations for publisher Bethesda Softworks, confirmed to Kotaku that the studio canned the game it was originally working on and began anew.
"An earlier version of Doom 4 did not exhibit the quality and excitement that id and Bethesda intend to deliver and that Doom fans worldwide expect," said Hines. "As a result, id refocused its efforts on a new version of Doom 4 that promises to meet the very high expectations everyone has for this game and this franchise."
Kotaku cites anonymous sources saying that ZeniMax Media, parent company of Bethesda Softworks and id Software, told id to implement a "long-overdue reboot" of Doom 4 in late 2011 because the game as it existed at that time didn't meet ZeniMax's expectations. (The image above is a piece of art from the old version of Doom 4 that leaked in February 2012.) The company also reportedly canceled a sequel to id's 2011 shooter, Rage, and directed the studio to focus all its efforts on Doom 4.
That focus also entailed the shuttering of id's mobile development branch, which Carmack confirmed during his QuakeCon 2012 keynote address.