That's somewhat true. You never create big ball of mud in one go, it's a process. Process of introducing small "dirty code" changes into existing code base. I

That's somewhat true. You never create big ball of mud in one go, it's a process. Process of introducing small "dirty code" changes into existing code base. I treat writing clean code as "kata" or "habit". I feel like once I start writing dirty code more often it will translate to clean code side of things. I will continue to think of clean code as a practice, not necessity. Also there are many small thing you would NEVER do even in dirty code like if statements that are hundred lines long, or having some unexpected side effects, etc. So if we agree that clean code is very very subjective, we must agree that "acceptable amount of dirty code" is subjective too.