[zo1]

Until you realize that you have X different implementations of the "same" functionality. All because no one bothered to look at existing items, or never bothered to make their code a little bit generic so that those that look at it later on know how to adapt it to their needs.

In essence, they're both partially to blame. There are times when generic code is unneeded, and other times when it will get used in the future. The trick is to know the difference, before it's too late and you have X different variations of similar functionality.