Others are just plain bad. This is a tough one to answer without getting into the debate about our specific roles and titles. I agree with most everyone else at the conferences that the continuing debate about what we call our industry is futile and that we are nowhere near an agreement on our job descriptions. But, to answer your question, I have to get into it a little. I actually believe the analogy to physical architecture lies in comparing it to web design as a whole, not just to information architecture.
Architecture involves the designing and building of buildings.
Web Design involves the designing and building of web sites. However, when you look at the roles that the individual players have, the analogy changes a little. An architect does not design and build a building alone no matter how large or small a project is. On small projects, the architect is the most active player in the first three stages mentioned above and oversees the last stage, although various specialists are involved throughout the entire process. On large projects, various architects with different specialties are involved, and there can be several architects overseeing the project.