This might actually be one of those times that skill comes into it.
If a new Halo'r starts with the AR (it really wouldn't matter what weapon) he/she isn't going to be skilled enough to use the pistol mid-ranged and switch in the AR for close combat. It's a strategy that takes some effort.
"Opinions should be a result of a thought, not a substitute for it." http://i.imgur.com/FwBee.jpg | http://i.imgur.com/nfZQy.jpg
I personally use firepower and have the AR and a precision rifle, usually the Carbine. A weapon for every situation is smart IMO. About the enter the middle area on Exile? Whip out the AR and outgun the people using the DMR in CQC. Entering a place with long sightlines? Carbine and drop fools at mid-long range.
I'll just have to get a full apology from you later. RARITYCATCHME.