As with everything in the game, higher skilled players adapt.
Explosive remains a group affix, but at higher skilled groups (key level doesnt matter), you know <insert person playing X here> can handle it, depending what you pulled you know "Game is broken, 15 explosives inc in 5 seconds" and everyone will deal with them, etc etc versus "I literally pulled 3 mobs, 2 explosives came out and no one even moved".