In Halo we could ignore little things like bullet drop, because we were freakin' space marines, but I think that Destiny, with it's more gritty feel, should incorporate bullet drop in sniper rifles. Go to the link, you'll see that the almighty .50 BMG has to be carefully compensated for to produce a headshot. (There are, of course, lighter rounds that I have used in real life that have much less drop over medium distances)
Now I suppose our Guardians could have scopes that compensate automatically (The military is already working on/has finished such scopes), but I think it would balance gameplay if only Hunters could snipe without drop, this would even out PvP a little more since we're assuming Hunters have much weaker armor than a Titan.
I have no problem with people who are avid snipers, I use them a lot in games, and have gotten all of the death threat xbl messages to show it.
Please tell me what you think, my opinion is narrowed by my own gaming experiences, and I appreciate any feedback!