If I fall, and I am 68 years old and the chances get greater each day, the last thing I want in my pocket is a fixed blade knife in a leather sheath. If that knife is sharp there is a good possibility it will puncture the leather and stick into you somewhere. Now a Kydek holster may be somewhat safer but less comfortable.

Heck, I will not carry a fixed blade knife on my belt unless it is in a kydek holster and then I would prefer it be in my backpack if I have one.