Opening Hours

Someone explain to me how it is that the majority of service industries can only manage to open 10-4 each day and still survive? Why is it that the majority of the work force manages to work at LEAST 9-5 and yet banks, post offices, any government department can only manage to staff themselves for a few hours a day. What's more someone explain to me how shops manage to make a profit when most of their clientele are still at work! I really don't get it, I feel like shouting to all the shops that are closed when I finish work at 6:30 to stay open for another hour or two and I would actually be able to buy something from them! I can't be the only one in this predicament.