Haven't there been three double engine-failures in commercial jets in about the past year? There was the Airbus into Heathrow and the Hudson river landing. Wasn't there a third?
The desire for a second engine appears very rational, even if it's not backed up by real-world reality shown by the accident statistics. The stats are very clear though. Whether or not you have a second engine, a second alternator etc won't make much difference to your overall risk exposure. Where the safety really improves is when you have a second pilot. It's clear you'd be far safer with two pilots and one engine than the other way around. Yet it's interesting that we don't hear many people admitting how unreliable a single pilot is and saying they wouldn't fly without a backup.