next you're going to tell me that the guys who drive locomotives aren't engineers
You're using engineer in a highly context specific way; yes, in some contexts, engineering is a licensed field, but the general meaning of the word is:
> Engineering is the practice of systematically applying natural science and mathematics to design and improve systems, devices, or processes that solve problems under constraints.
Which is a word-for-word description of the sort of work (…some…) software engineers do.
(Perhaps less and less "systematically applying science" these days with the slop fest out there … but the field should be doing engineering.)