It's not just English. Some words exist in normal english and law english, and yet have entirely different meanings. You have to study to understand the meanings. You have to study to understand the contexts in which words appear and in which they are even relevant.
Not to mention the heavy salting with latin words and phrases.
Every profession has terms of art in it, including engineering, science, and construction.
Having engineers in HN complain that they need to learn something in order to understand it is a pretty bad look.