High-power bike lights originally were designed and marketed for mountain bikers, so tend to be spot or flood beams. For various reasons, they have crossed over to commuting use, but as discussed above, the beam shaping is all wrong for on-road use.
Mind you, some manufacturers do realise that on and off-road night-time riding have different beam requirements - for example, USE's Exposure range of lights features a road-specific model which has main/dipped beams, realised by using different lenses for the two LEDs.