It's under your caps lock key somewhere. You must have inadvertently hit it when you edited
Wikipedia's text to make the commentary appear to be part of the definition.
A good rule is not bound by, well, rules:
The laws of thermodynamics aren't simply about energy.
Murphy's laws of combat aren't actually about the military.
The Peter Principle isn't just about bureaucrats.
That's why people outside those fields know what they are.
Yes, the Peter Priniciple is simply an observation that pointy haired bosses promote people based on performance in their previous positions while disregarding their suitability for the position being promoted to. And the Bible is simply a book that you find in hotel room desks, and the Earth is mostly harmless. But what does it all mean? The whole point of the Peter Principle is not that you should be careful in your staffing choices or even have to be within an organization, it's that
advancement stops because of lack of success.
Promotion is a result of success. DeLorean did very well at every level within a large company, and decided that he was therefore capable of running a whole company. If you still need to see him as being inside an institution, look to the governments and banks that give and lend money to startups even today. The Bank of America and the British government looked at his performance as a GM executive and cheerfully bankrolled his new company.
But niggling little details got him, like the need for an experienced workforce. The engineer in him looked to put his factory in a place with high unemployment so the local government would give him a sweet deal. The inexperienced CEO in him didn't realize that if everyone in the factory was new to their jobs, quality just wasn't going to be there.
The legalities of entrapment aside, smuggling coke is a bad idea. A great engineer may be confident that he has all the details worked out, but even a mediocre CEO should know enough to turn it down. Fail.