This enabled the IIci to restart automatically if power was lost and regained, which is just how you would want a server to behave. I have a personal bias here, which is that we waste enough energy already, so why not turn things off when they aren't being used. The situation is getting worse now that we have so many appliances that are always on to power remote control or even the clock. Each appliance may be more efficient then they were 20 years ago, but we have so many more of them. But if you aren't swayed by the environmental arguments, then the quick answer is that it really doesn't matter.
Electronic components prefer to be at a constant temperature.
So leaving your equipment on reduces thermal shock and voltage surges. But most equipment these days is so reliable that it doesn't matter much. I've been turning my system off every night for years, and have never experienced a failure when I turn it back on. But you will hear the other side argued. Take a large company with hundreds of computers.