Why? Because I think they are the best.
The chisel grind...
Planes versus wedges - you can't beat a chisel grind for removing material
The unground side has excellent cutting geometry - it is flat with nothing to catch or cause much friction
Easy to sharpen - no need to maintain a bevel on each side, just sharpen on one side, it is easier and takes less time
Strength at the weakest point - the ricasso on chisel ground knives transitions gently through the plunge to the edge instead of quickly narrowing and making a bend point
Increased cutting performance - they do work better in the hand the bevel side is ground on - right handed/right hand bevel
the performance is shifted to the cutting side, I find a chisel grind to work faster because of this
Whatever you are cutting falls off to the correct side, this is especially useful during food preparation or carving