Probably a good part of these people is just being selfish.
They completely ignore the increased suicide rates and other effects the switching of the clock has. It even affects the cows of farmers. It has negative side effects for millions of people, but NOOOOOO, those poor people who need to get up earlier, they'll be having a much harder time!
> The fact that short days and darkness cause so many people problems in the winter tells me that amount of sunlight really matters to us.
For the greatest part of our history we've spent our time outside, not sitting in artificial caves with artificial lights, hiding from the sun. If you want something that tells you why the sun is so important, take this instead.
If that doesn't work for you, remember that having enough exposure to the sun is vital for your body to function properly, both mentally and physically. We'd not be producing "Vitamin D" by being exposed for some time, if the sun wasn't an important factor in our existence.
Please tell us more about it!