I used to think 'meh' when I heard about these things; a lot of people leave their PCs in sleep mode so they wake up in a few seconds so why the need for a fast cold boot?
Then I heard the statistic (not verifiable), that if all those people in the UK with Sky TV boxes switched them off, rather that leaving them on standby, we could switch off one power station. Although these things are on a small trickle of power, their vast numbers add up to a lot of electricity.
So a faster cold boot might encourage a lot of people to properly switch off and save a whole lot of combined resource.
Herbie