Fortes should make good rock speakers because their high sensitivity will turn a small amplifier signal into big, loud music with fast, unclipped transients, which make drums, cymbals and the pick on a guitar jump out more like real life.
The main limitations of the original 3-way horn-based Klipsch's are that the individual drivers are anything but time-aligned (which is more important to orchestral and acoustic music), and you have to be within the horns' dispersion angle to hear things right. When you get outside that sweet zone they can sound like being sideways to a megaphone. Their bass also doesn't extend down as far as something like a Totem, but the Forte is good and strong down to the 40s which is fine for rock.
The main limitations of the original 3-way horn-based Klipsch's are that the individual drivers are anything but time-aligned (which is more important to orchestral and acoustic music), and you have to be within the horns' dispersion angle to hear things right. When you get outside that sweet zone they can sound like being sideways to a megaphone. Their bass also doesn't extend down as far as something like a Totem, but the Forte is good and strong down to the 40s which is fine for rock.