The DMR is the crutch of a bad player, not saying that everyone who uses it is bad at the game. If the DMR is nerfed( rate of fire, damage, bullet magnetism, etc) I guarantee you will see people who are good players still use it effectively. While the bad players will cry that it is broken and useless.
I almost never use unless I pick it up off the battlefield as a last resort. It is boring to use and reminds me of playing Reach.