Don't kid yourself, Tyranitar would fall to UU and perhaps even lower if it didn't have Sand Stream. It's weak to virtually every single attacking type used by the most common OU and UU pokemon and its speed sucks. Its primary STAB has terribad accuracy and its secondary STAB gives a Justified boost to the Musketeer quartet as well as Lucario. 95 base special attack is decent but other than hitting something with a 4x weakness to Fire Blast or Ice Beam it's not doing much.
If Politoed and Ninetals are NU material without their abilities, it's not hard to see Tyranitar dropping to UU or BL2 if it didn't have Sand Stream.
Don't get mad, get gllad. http://cdn0.sbnation.com/imported_assets/404951/chocula_medium.jpg