We don’t have to diminish their accomplishments, no; we choose to.

Oh, wow, TIL.

At least in civil, the reason is because the professional engineer (PE) stamps all plans and assumes responsibility for said plans by doing so. Plans cannot be built without a stamp. This is the case because someone has to be found liable if a bridge should kill people, and it shouldn’t be the technicians, designers or EITs under the PE, because they don’t make nearly as much. With great pay comes great liability.

All engineers not just civil?

I think that’s only a civil engineering thing.

Source: work in the industry, and “Civil Engineer” and “Professional Engineer” are legally protected titles. Other than that, it’s fair game. Like, there are “Design Engineers” in the civil sector that don’t have their Professional Engineer certification.