Because they are referring to engineering disciplines that predate all of the stuff you mention. When mechanical, structural, civic, etc engineers sign off on a design (stamp it) the incur personal liability if there is a defect in the design that kills someone or causes damage. There are certifications for telecom design and processes that require them to stamp designs, but otherwise most of what is lumped together as technology doesn't constitute engineering from a legal or historical perspective. However the titles sort of took off and created two sets of meanings.

If software engineering was treated as engineering in the way that mechanical or others forms are, you would get a degree, get an entry level job at a firm as a junior, and after a few years, study and get certified to stamp designs/code systems, etc.

Now, outside of places like code for flight systems, medical devices, power plants, etc there isn't a need for that kind of rigor, but those are the areas that would require licensing if it was available.