First, most software developers are taught "computer science" (or an imitation of it) in their formal education, not engineering.
Second, software is mostly not engineering. Engineering is very measurable. But software includes a lot of design and craftsmanship. If software dev. were restricted only to the portion that could reasonably be called pure engineering it would be a very, very small subset of mostly systems code. Indeed, a good hunk of software dev. could properly be called merely arts and crafts, under such a strict interpretation.
I think this explains some of the religious wars, because the debates are more aesthetic such as "do you prefer charcoal or pencil" than engineering "which is better steel or aluminum", because purely engineering questions tend to have very much more straightforward answers.