"I released source code under the MIT license and people are now using it to their financial benefit. Who could have possibly seen this coming?" Why does this keep happening? Why are so may developers blind to this obvious outcome?
MIT was always the easy default that every project used, you just select it from the GitHub dropdown and you are done when setting up a new project. I think you can't really blame people for using it. Especially when your project is new it's also not often clear that this project will become something more serious later where you have to worry about such things as people cloning your project.
A lot of people say that it can prevent these situations but from working for large enterprises, a lot of the offerings that are created literally don’t even change the code. Thus they have nothing to contribute and have no obligation to release any source code.
GPL also does not prevent the corporation from building software in front of whatever GPL service it is. Kind of like the Linux kernel, why bother changing the kernel when you can build software in front of it and not change anything and thus have nothing to release.