I know many profs who decided to switch from industry to academia because they had enough money and wanted a less hectic lifestyle. A very large number of profe

I know many profs who decided to switch from industry to academia because they had enough money and wanted a less hectic lifestyle. A very large number of professors actually do contract work for companies. Even a former Master's supervisor of mine (who is officially retired) still does consulting with companies (typically game developers as he specializes in splines in computer graphics). I'm actually in Engineering and at least in Canada, there's actually an accreditation body that reviews the engineering programs to ensure they live up to a standard. If the program meets that standard, the graduates only have to take a law and ethics exam (in addition to the experience requirement). If you're outside that system, you have to take a series of exams on the material. I know that it's different in the US, though. I believe that you do have to take a set of exams on the core material for your type of engineering as there's too many programs to properly vet all of them.