I have Quad 57's for Baroque, but they are unsuitable for AC/DC at
realistic SPL. Of course a speaker SHOULD be able to play all musics,
just as it SHOULD be 100% transparent and uncolored.
Quad 57s do great on rock within their volume limitations. A lot depends on your room size and how lively the room is.
I find pinpoint imaging does not hurt rock at all. Check out King Crimson's 'Islands' LP; lots of things going on in that recording; the better your stereo the better it sounds! Black Sabboth's 'Paranoid' (white German Vertigo pressing) can bring many systems to their knees in a matter of seconds- and the recording is spectacular- the better your system the better it sounds! The best sounding Pink Floyd LP is actually a bootleg- entitled the Screaming Abadabs 'Rhapsody in Pink' which is a BBC recording of Pink Floyd performed in the BBC studio before a simple Decca stereo tree. Pinpoint imaging really helps as the recording has depth and dynamics just like the best classical recordings, and the better your stereo the better it sounds!
I think there must be an assumption that somehow rock is always poorly recorded and should be dreck played as loud as possible. This is really selling rock short, but that's the only explanation for why people must also think that there is a particular speaker or type of speaker that can do rock better. There isn't- that is a myth. The better your speaker, the better the rock will sound and there are many excellent rock recordings!