Bartosz, your ramblings are not about maintainability they are about ownership which you, evidently, do not have any idea what is or do not believe in. So I suggset that you, to practice what you preach provide a link to every bit of code you have produced, so everyuone can have it for free and compete with you without investing any effort.

So who cares if code that doesn't work is maintainable, if it's not maintainable by them? I buy a close-source program, I find it doesn't work, I write the user support and they never answer - why should I care if the original source code is maintainable?
You should not "care if the original source code is maintainable", you should care about dealing with a reputable company

But who DOES care about code maintainablity? Well, first off, your boss. Management loves to have maintainable code, because then they can fire developers at will and the new ones blend almost seamlessly into the development process. No need for raises, bonuses or such, just replace whoever complains. And the second in order are the developers, because maintainable code is, well, easier to maintain. And writing unmaintainable code in order to secure your work position is considered unethical
Oh no, not that old song again, It's been a while since I heard "if I make good code they can fire me" I have, actually, in my career, fired several people just because nobody else could understand their code. Yes, you take a hit with the need to rewrite the code, but end up with a group that can function.

Oh well, maybe by NOT "the most important feature of a program is that it is mainatainable by Bartosz Wucke" you meant "the most important feature of a program is that it is mainatainable by ME and ONLY ME"?

There is no "ME" here the one thing you evidently cannot grasp is the concept of ownership.

Erik