The guy who designed it for Worf in TNG, was inspired by a Chinese single-handed weapon. That weapon was not widely used because it wasn't actually that good.
Still, the deer horn knives are theoretically a sound choice for a weapon, provided your goal is to disable the opponents while likely getting skewered from range.
The Bat'leth is just a useless hunk of metal.
It was designed to be showy and look interesting on camera, not as a practical weapon, and it really does fail as a practical weapon.