Programming is a lot more than logic. You have to conform to conventions which you just learn over time.

The reason OS is written the way it is, is because partially Korn uses common naming conventions and on the other hand implements his own. Naming conventions are mostly ignored by beginners and that's why most of the code looks like crap in the beginning.

Not to mention having background knowledge allows you to write much more efficient code. You could use a 64-bit data value (e.g. int64_t) for iteration purposes, but when you optimize your app to run in x86, the iterator cannot be stored inside a single general purpose register.