Jim,
Agreed on all points... well, almost all <s>.

>Now I do think you are over-generalizing when you say that "Poorly written code is already bug-prone".

We might be splitting hairs and arguing each other from the same side.
I don't care if someone's style was different or even downright weird.
Hey, if it works, I am going to leave it alone.

More accurately about poorly written code:

*Changes* to a ball of spaghetti are absolutely bug prone.

It is the same with spaghetti I wrote and spaghetti I inherited.

Changes to one part of a monstrously long procedure will inevitably have side effects. Bad side effects.