AC/DC play a certain style of music and do it brilliantly. It may be relatively simple to copy but if it's that easy to create, why aren't there a host of other bands doing the same thing and making lots of money?
Angus is a bloody good guitar player, ok he's no Clapton or Beck but he does what he does very well and puts on a great show at the same time. Malcolm is an underrated musician, his right hand has driven some of the biggest-selling rock albums of all time. Clif Williams and Phil Rudd hold down the rhythm nicely at the back, it's easy to dismiss what they do but laying down a groove, even simple one, is no easy task.