LogFAQs > #986227577

The only reason Light failed is because he let the default death of the Death Note kill all his targets, and even said he hoped people would notice the pattern as he wanted everyone to believe there really was a god out there punishing people.

Admittedly, if you were to make the deaths accidental somehow, I feel like people would notice a sudden surge in deaths that are, for all intents and purposes, accidental. People might think there's a god or some otherworldly force out there and everyone getting paranoid of every little thing they do somehow resulting in death might be even scarier than expecting a random heart attack.