Customer service

At the co-op orientation, they showed a video on customer service.  One of the things that was mentioned was that you should talk to each customer as an individual.  We all know that we hate when company representatives try to talk to us by reading from a script.  What I don't know is why companies keep doing that.  I mean, if you know the first thing about customer service, you know what a huge turnoff it is, so why would you require that your employees do it?