We don't build bridges, we make valuable things people will give us money for. We solve problems. We respond to rapidly changing, conflicting requirements.
How many suspension bridge projects have turned into skyscraper construction projects over the course of two months? Now, how many web startups have radically changed their idea? Flickr started as an online game, you know.
I'm extremely suspicious of anyone who calls themselves a "software engineer."
When I was in school this article was required reading. Your life and safety depend on software engineers every time you dial 911, ride an airplane, etc. Not everyone is writing Facebook applications :)