Take a minute and understand that you maybe left your home that you must pay to maintain, and it probably has a kitchen that you could have cooked that hamburger for yourself. But that would have meant that you had to buy all of the ingredients you needed to make that hamburger, along with the customary utensils that allowed you to eat that hamburger, and then had to clean up everything from cooking yourself that hamburger.
When you go someplace to buy yourself a hamburger that business must contract with other companies to get all of those things to make a hamburger. Since many places can make any hamburger, they probably also went above the norm to provide many sides that you could of ordered with that hamburger, along with almost every kind drink that anyone could order.
Remember that business is not just catering to your needs, but they are trying to build a viable business that attracts enough people each and every day to come to. That establishment is just one of many, and in order to stay in business because you on a whim wanted a hamburger, they have to make sure that their hamburgers always stand out above the rest.
Lastly, you could probably go to a White Castle, or someplace real cheap for an ordinary hamburger, but then the food itself might not be edible, and it might come back to haunt you many hours later. Sorry to all of those White Castle fans, but the cheaper you make a hamburger the harder it is to digest it.
I am glad you think paying someone to run a business is stupid, but in today's economy it requires you to not only pay someone better, but to maybe provide them with a day off once in a while, and God forbid they might want some kind of benefit, otherwise they will leave you as quickly as they can. But I am glad you think this is all stupid because you decided on a whim to get yourself a hamburger and wondered why it cost more than you could have made it at home. But then then your home would need a kitchen and someone like you who is not intelligent enough to make a hamburger for yourself.
But like you stated, you just cannot fix stupid.