Only if you can aim, though.
I'm glad if I don't have to waste an entire magazine on one guy.
You'd be surprised at how much I miss past mid range. I mean, yeah, I can certainly aim better than the average player, but there *is* shot spamming to do. Rhythmic shot spamming below maximum RPM, but shot spamming nonetheless.
(Though I think DICE has tweaked the headshots to be 1-2 kills now. I did notice a headshot bonus popping up on that. Though it's DAMN hard to get headshots for me with the DMR against Cabrine/etc. with suppression and all that stuff going on, plus big/huge maps)
Headshots are a 2SK. They're not particularly hard for me to get if I'm fighting a "headglitcher" up to mid range (then again, I don't really go for headshots), and actually I would see distance fighting (except at sniper range) as an asset the vast majority of the time. Most people won't even bother distance fighting a DMR and / or react too slowly because they expect AR fire.
Locker is the obvious exception here, but I always use the M16A4 there so I don't need to deal with that haha.