in reply to Best practice or cargo cult?
One of the things that TheDamian emphasized in his talk at TPC that became the book PBP was that the rules he was espousing were the rules he thought were important. He didn't expect everyone to agree with every one of the items, but that he wanted each person to make a conscious decision about what they wanted to follow and stick with it. Having a set of default behaviors based on choice rather than habit was better than the opposite.
So best practice is having a consistent behavior and cargo-cult is doing something because someone else told you to, without understanding the reasons yourself.