|But why worry about style? Who cares what a program looks like if it works? Doesn't it take too much time to make it look pretty? Aren't the rules arbitrary anyway?|
The answer is that well-written code is easier to read and to understand, almost surely has fewer errors, and is likely to be smaller than code that has been carelessly tossed together and never polished. ... Some of the examples in this chapter show what can go wrong if there isn't enough attention to good style. Sloppy code is bad code - not just awkward and hard to read, but often broken.
The key observation is that good style should be a matter of habit. If you think about style as you write the code originally, and if you take the time to revise and improve it, you will develop good habits. Once they become automatic, your subconscious will take care of many of the details for you, and even the code you produce under pressure will be better.
- Kernighan and Pike in 'The Practice of Programming'