Well, depending on the situation, it might not help. For example, if your brakes can produce 1000 lb of force, but the max friction force of the tire is 900 lb, a 3% reduction in area won't really matter. Plus, the coefficient of friction doesn't drop as quickly at higher temperatures with drilled rotors, so a blank rotor could drop below the 900 lb threshold at a lower temperature than a drilled rotor. It is an oversimplified example, but you get the idea.

Yeah, in that case, you don't have much of a choice.