I think it's inspired by Brutal Doom in that BD reminded many DOOM players what the game was really about. I think over the last 20+ years of playing, DOOM became pretty passe and the energy of it had diminished. I remember in late 2012, a BD trailer was released and one of the comments was "this is the only mod that makes doom more like doom." And the spirit of what he said is right.
I think that revitalization is what inspired id, more than 1-to-1 ripping off glory kills or whatever.