I agree that it is a grammatical problem. You can’t “be” an IT or a cable like you can "be" a doctor or lawyer, but you can be a person who works with IT or with cable. So you are the cable or IT person (guy).
And the IT industry comes with many specialized areas as does medicine (podiatrist, internist, gastroenterologist, cardiologist, etc.) and law (divorce law, corporate law, patent law, criminal law, etc.). We generalize people in those professions as doctors and lawyers even though a person in one specialty may not have the slightest clue how to go about doing what another specialist does.
If you aren’t actually involved in the industry, the technical nuances that may be defined by titles can be meaningless.
When I was in 1st grade in the very early 70’s, my class did a project where we assembled a notebook of our father’s jobs. Each of us received a mimeograph sheet (do you remember these old purple smelly things?) to write where our dad worked, what he did, and to draw a related picture. I had done my due diligence and asked my dad the night before what he did for work. He told me he was a “Systems Analyst”, and he worked for a company that made special tools for the automotive industry. What meaning and interest is that going to have to a 1st grader in the early 70’s?
When it came time to write / draw our stuff, I couldn’t even remember what my dad had said, so I looked for something interesting but not obvious (that could obviously be proven wrong). I wrote, “My dad works at […]. He makes balloons.”
Even a 1st grader can understand what that means!