lol. They sell them because people ask for it. merc Amg execs even admitted that.
My stoptech str kit on my race car has no cross drilling. Wasn't even an option.
Go look at any WEC cars brakes. Slotted only.
Cross drilled are for disposable rotors. I can't afford to dispose of them. If you look at a proper set of heated rotors, an rotor that actually spends time at its proper temp, you will see when it cools thousand and thousands of tiny cracks.
On a rotor with out holes, these cracks srt on the surface layer and don't have the ability to effect the thickness of the rotor.
When you add holes, cross drilled, those cracks now form in the walls of the holes drilled and now have a way to split the rotor. This is where the cracks form.
Brembo, ap, Alcon Stop tech, etc sell cross drilled rotors because people demand them.
Race teams, especially endurance racing use slotted rotors to eliminate gas pockets under the pad and to sweep the pad and that's it.
I'm sure you will find one or two race cars that use drilled rotors but the majority don't.
Even top level time attack cars, the one lap
Wonders, where weight is everything, don't use them.