George, you are right, so I'll put that quote in context:
A project is not going to turn out great unless it is a fun experience for everyone, including the client. So you want the client to be involved, and you don't want him griping that everything you are building is going to kill his game ... if you do that, as John suggested, the course may well get changed after the architect is gone.
With that in mind, we like for the clients to feel free to provide us with input, as long as we are free to ignore the parts we don't think are going to work well.