My experience has been that this isn't limited to engineers. I'm sure most people here have had people from other departments tell them how they need to do their jobs in one way or another.

For example, there are always at least a few people who you have to consult regularly because their tickets are always written how they perceive a problem should be solved rather than explaining the underlying problem to be solved. Then there are the sales and marketing types who like to dictate how the UX of the front-end should be because they like to retell anecdotes to prospective clients about how they solved a problem. Then there's the guy who hands you a spreadsheet he's maintained for years and tells you he wants you to put something exactly like it in the flagship product as a new feature.

I'd say celebrities and creatives in general are often big offenders here too. Lots of actors/athletes/musicians acting like being good at what they do means they're also qualified to talk about science and engineering. And a lot of reviewers, documentary creators and specialist writers that decide to wade into discussions about topics they have no knowledge of/cover something they're new to, only to look ridiculously out of touch as a result.

See the Nostalgia Critic review of the Wall. Or the Alex Meyers review of Obsession.

>My experience has been that this isn't limited to engineers.

To some extent, but the most severe form does seem fairly unique to engineers, specifically programmers. That is, I've met many arrogant lawyers and doctors, but never a lawyer or doctor who assumes they could program a computer due to their legal or medical expertise. But I've seen many a programmer assume that because they are proficient in programming they can confidently and authoritatively expound on all other areas of human endeavor (those being obviously inferior and trivial in the face of their own).

Medical doctors and physicists also regularly suffer from this. It’s more of a disease of expertise in general, it seems.