I think that you're looking a lot at how the US is and not so much how other countries are. Take the Netherlands for example. It's only in the last couple of years that I've seen grocery stores open until 9 in the evening, instead of closing at 5 with the exception of Thursday or Friday (late shopping night). They're still all closed on Sundays. There are 'nightshops', but these are small and sell only a few essencials, and they are really only found in cities like Amsterdam. Credit card support at all hours? Hah! Credit cards work through bank accounts, so you get the same hours as for banks (something like 9-4, except on Mondays, when, like most shops, they don't open until the afternoon). Public transport stops for a few hours--for about 5 hours in the city I live in. Try getting a pizza at 4 in the morning. Now it's probably clear why I said in my other post that I need flexible hours just to get anything done for myself.

Will this change? It's already changed a little bit, and it will probably change a bit more, but it will take a while before there is acceptance for even the amount of night jobs in the US, in my opinion. I believe that working at night is considered unpleasant and therefore people who work at night get extra pay (Jouke or ar0n would be better at verifying or refuting this). It just costs more to have people work at night (you need more lighting as well).

But the main reason shops aren't open at night is that it isn't seen as fair and isn't allowed without a special permit. It's thought that if large supermarket chains can be open all night, smaller grocery stores wouldn't be able to compete (which is probably true). It's also thought that if smaller shops were forced to close it would be a loss to the community. This viewpoint can also be seen in the US: for example, many communities have objected to the establishment of Barnes & Noble bookstores on the grounds that the company deliberately pushes local bookstores out, thus robbing the community of the culture surrounding these bookstores.

The future could hold a 24-hour monoculture. But it might not.