I'd Love To Help, Just Give Me Five Days...

I can't figure out why there are still 'business days', at least in regards to the banks. Everything is run by and on computers now. Interest on loans and credit cards is calculated and charged daily. Yet when I make a payment or process some funds, it takes five business days for computers (which can process information almost instantly) for that payment to go through. That shouldn't be.
It should be possible to, within a single day (even a weekend), have that money, which is only electronic anyways, go from my account to wherever it is going. Why does it take five days for the computer to move a bunch of ones and zeros to another computer. It shouldn't. I can instantly look at my account and my credit card, so why can't the money flow that quickly? Does it take five days to verify that I have the money there? No. I just checked and it was there. Does it take five days to fly across the country? No, it takes a few moments to sync up security systems. What's the wait? I can't figure it out.
I guess there are some explanations. I'm just not sure how cynical to be. Maybe, because of the sheer volume of information, the computer systems aren't able to handle everything instantly, and delaying is the only way to keep from crashing everything completely. I have trouble truly believing this because it seems like too big of a coincidence that the computers need the same amount of time as the banks needed in non-computer ages.
Which makes me think that it is a resistance to change. Banks have always operated on less convenient hours than most people nowadays live. I suppose it is a holdout from the early days of banks when life was vastly different than it is now - when there wasn't 24 hour everything. In some ways, the current world is a bit more conducive to banking hours because there are more people who work evenings and weekends, leaving them time during the weekdays to make it to the bank. But still, the world has changed, computers, evil though they may be, are able to do things much faster than we ever thought possible in the past, so why do we still need business days to process something? Why are 'five business days' really 'one week or more'? Even with taking five days, the weekends shouldn't affect the time. If we really need five days, why do we need to worry about the weekends? Do computers take Saturday and Sunday off? Does my Toshiba know that Sunday was Christmas so it decided not to operate that day? The only way it makes sense is if there is such a massive resistance to change that the banks and financial institutes have decided to just not change it even though they could. They're scared of the technology and so they hide from it as best they can.
The only other explanation I can think of is that it is a conspiracy, if you will, of bank fees and profits. By taking the extra time they can increase the money they get from interest and from fees. Poor timing means that late fees can be charged. They have the power and their isn't much we can do, so as long as they are looking for maximum profits (and that is the heart of capitalism after all), then ease, convenience and user friendliness take a back seat to profits. The only way things get better for the consumer is if it will create more profits for the company. There is no altruism in business. Sweat shops exist because consumers demand lowest prices and businesses want maximum profits. Something's gotta give, and it is those who can be easily exploited that are. Even things like fair trade can be viewed fairly cynically - the companies that do it are mostly interested in looking good for the growing segment of socially conscious consumers. They would rather be buying their product for the lowest possible price and selling it for the maximum possible price. And that was a bit of a tangent, but not much because the principles apply to banks and financial institutions (though I don't think there is much slave labour in banks - they probably just pay their tellers as little as they can, but it's nothing like sweat shops).
Sadly, I think it is a combination of resistance to change and addiction to high profits. The world is changing, but not as much as it should be, and not for as much good as it should be. I can understand a resistance to change - I'm someone who likes routines and comforts. But I have way less interest in profit and business.