Good programmers use their brains, but good guidelines save us having to think out every case.
I have spent way too many hours in arguments over coding guidelines – where do we put the braces, are we using underscores or camel case? I have come to the conclusion that within reasonable boundaries I don’t care, but I really like the guidelines to be consistently applied. I don’t want to spend any time thinking about how we differentiate member variables, or what the convention for naming include guards is. There are much more interesting problems in the world.