>>13881682those clauses are to prevent luck-based wins and variance which, spoiler alert, already happens with these clauses in place ala
-random crits
-random status induced off of moves such as ice beam, scald, fire blast, thunder
-losing speed ties due to coinflip
-flinching off moves such as iron head, waterfall, zen headbutt, air slash
-not getting a high enough damage roll, because moves (with the exception of things like dragon rage and sonicboom) do not do the same amount of damage every time; they vary in range by about 11%
and those occur with great frequency throughout battles. there's no need to increase the variance further by letting horn drill, sheer cold, etc, be legal. that just takes skill from the game and makes a crapshoot, which nobody actually wants. smogon AND nintendo don't allow OHKO moves to be used, so this clause isn't exactly there for no reason.