it's because people whined so DICE nerfed it... not that it was great before, but now it's really bad.
I dunno, it's not bad on Metro Rush first set to counter C4 on crates. Of course, I lagged that game and we lost because people kept arming and no one wanted to rush into the building/throw grenades and hold it while I was lagging but hey... Calion and I tried. (And then I swore not to play the game until either Vehicles DLC and/or connection is fixed. Whichever first.)