The devil you know is better than the devil you don't. Every un-normalized database I've inherited has been a colossal mess and practically unusable -- especia

The devil you know is better than the devil you don't. Every un-normalized database I've inherited has been a colossal mess and practically unusable -- especially if there are important relations. A de-normalized database is a thoughtful process which I rarely see a developer do -- they just want to get programming and don't think about long-term issues.