I resisted the AR movement for a long time, just had no use for a .223 caliber rifle. That said none of my rifles are range toys, and I own an AR-10 clone (DPMS LR308) and I am building a .300AAC AR-15. Just got a DD upper receiver and am awaiting my barrel.
My reasons had nothing to do with TEOTWAWKI or SHTF,(I personally think those guys all have a misguided Red Dawn Fantasy but so what)
I shot an M-110 in Afghanistan and I wanted something similar, I hunt a lot and if my rifles don't fulfill one my hunting roles I don't buy them. I don't spend a lot of time on the range and i don't shoot competitions, would rather spend my limited spare time hunting. I don't need safe queens and I am not a gun collector, I am a firearm user.
I like the AR platform, I enjoy the ergos , the light weight and low recoil and maybe because other than bolt actions, due to the Army I have spent a lot of time with it. I know it really well and I know what it can do.
I guess we all have reasons for what we buy and like, thats the fun of being a firearms enthusiast we all have a seat at the table. For example my brother is a pistol guy, shoots USPSA, etc. I have no use for handguns, I own a couple but its not my firearm hobby, Im a rifle guy doesn't mean i think people shouldnt own handguns, just like my brother doesn't think people shouldnt own ARs or AKs. To each his own regardless of what they intend to do with it.