It's not much about advanced Dizzied, it's about quantity. The books make it fairly clear that even driving a car is risky business around a wizard, and casting spells works very well to erase anything computer related in a pretty wide area. Think about the number of computers, security systems, cars, cameras, slot machines, bank ATMs, etc... everything would have a meltdown anytime anything went down on the Strip. We'd basically have to RP out in the suburbs, and where's the fun in that lol.