Why stop there? No PE no engineer.

You can arbitrarily gatekeep the title all you want, but the reality is that engineering is a group of concepts and ideologies that can be applied to many disciplines in many ways.

Just because the person doing the engineering doesn't meet your personal standards doesn't mean engineering isn't being accomplished.

There is nothing about the engineering process that requires a degree.

All that being said. A professional engineer is an actual controlled title. (You can't sign documents as a PE without getting the license, just like an attorney (JD) or doctor (MD)) but far and away most engineers, do not have this title, because most engineering jobs and tasks don't require it.

Finally, (in most states) you can work with no degree under a PE for four years, pass the FE and PE, get your title and build a bridge. So as far as the most stringent title goes, it still doesn't actually require a degree.

I think most engineers have an understanding amongst each other, regardless of their specialty, we can all teach ourselves to problem solve. So many math and physics classes as an EE just to get to my core classes. It definitely a certain type of person to get through the thick of it.

insulting to the workers

Then why do the workers choose to identify as such in public?

No one at Subway is going around calling themselves an artist.

It's exactly this. No one complains when IT infrastructure engineers design and build systems and call themselves engineers, even though they don't have a PE certification. So if they can do it, why not support staff?

Programming grew up in an environment where failure is cheap (relatively speaking). You might make a mistake that costs five, six, or even seven figures (I'm sure I've made at least one seven figure mistake), but nobody will die from it. When people could die, such as flight control software, different development techniques for formal methods are used. Those tend to cost at least ten times more than other methods, so they aren't used much otherwise.

If anything, we should lean into this as an advantage. Iterate even faster, catch failures faster, and fix it faster.