[DougWebb]

In most/all of the US states, you have to take an exam in order to call yourself a Professional Engineer, which is required for a lot of engineering professions and/or positions within an engineering organization.

Your four years of schooling to get an engineering degree had plenty of exams, spread over the four years. At most you only had to study for one or two of them at a time. The Professional Engineering exam covers everything you were supposed to learn during those four years, all at once. You can't cram for a test like that; you have to actually know things. That's the whole point: did you absorb the knowledge completely, or did you just get by from test to test?

It's done this way because, for most Professional Engineers, decisions have to be made which can cost people their lives if mistakes are made. You gotta know what you're doing before you're allowed to make those decisions.

For most software engineering mistakes aren't nearly that critical, plus for most organizations doing software development preventing bugs to the same degree that a Civil Engineer prevents bridges from failing is too expensive and not worth it.