So no one working on railroads before 1907 was a "real" professional? That's more than 100 years after the railroad was invented and took off.

The Bar exam in the US didn't start until the 1780's, so lawyers before then weren't "real" professionals either?

It's a ridiculous argument.

A better one might be that the externalities and opportunities for software engineering to kill people, or be directly tied to deaths or negative outcomes, didn't exist or weren't well enough documented until recently. As an immature field/industry that's not surprising, but it does point to a responsibility by the community to push for standards that don't currently exist.