I don't think "engineer" has a broad general meaning any more than "veterinarian" in the context of professions. I do think that "software engineer" does have broad general meaning, however.
So it would seem this ruling goes against historical usage.
Umm, no. It is true that train drivers were called "engineers" because they operated an engine.
But the title "engineer" goes back much further than that. It comes from "military engineer", where "engine"/"engineer" meant "machine" or "ingenious".
Military engineers have been around for a very long time. Around the time when the industrial revolution started, people who worked with non-military engineering started to be called "civil engineers".
They mostly worked on building roads and bridges, which is where today's "civil engineer" comes from. But in countries like Sweden, "civil engineer" (civilingenjör) has remained a title for all engineers, not just road/bridge-builders.
> having a certificate for engineering at all is a recent invention
Not that recent, higher engineering education started in the 1700s in Europe.