Another factor might be that the term engineer is a protected term, and not unlike doctors and lawyers there exist state-regulated tests to confer such a title.
I'm sure that a mechanical engineering course would be possible, but the course would have to clearly state that it cannot accredit the credentials to actually work in the field.
Seems obvious that a non ABET school would never give engineering credentials, yet community colleges still offer technical courses on mechanical and electrical engineering and even associate degrees in those fields. Professional engineering requires ABET bachelor's and passing EIT and then the PE exam plus 4 years professional experience.
I have a degree in Mechanical Engineering; I have not taken any professional licensing exams. There's an overwhelming majority of jobs that I could take in the Mech E field right now, without a need for the PE license.
I'm not sure the precise details, but there's an "industrial exemption" for engineers who work for a company that makes a product. Most of the MechE's in my department do not have licenses. One colleague is pursuing hers, but mainly on the grounds of "just because I can, so why not."
I got as far as an EIT but then went back to school and changed careers.
Engineers mostly need a PE licensure if they're going to be signing off on drawings and the like for regulators. Thus PEs are pretty common in civil engineering and, I assume, structural engineering in general. But most Mech Es aren't licensed in the US even if they have degrees from accredited schools.
I'm sure that a mechanical engineering course would be possible, but the course would have to clearly state that it cannot accredit the credentials to actually work in the field.