If you ever started enforcing this against the "contractors" that the satellite companies and Telcos hire it would have a chilling effect on the companies.
When you buy that "inside install/maintain" service from the telco, or have your dish installed that will usually be a contractor (AKA trunk slammer with a driver's license). I bet these guys don't even have a $30 occupational license.

WE Have surprised quite a few of them, license and permit required,

How did the satellite guy act when you told him about 810.21(J).

My guy cocked his head like a puppy and said "que"?

My 2 cents is the poor guy was hired by someone else that allows them to do whatever. And has no clue on what is required by him.
They just have him show up and work.
So the real culprit is the level above him.

I believe the precedent for allowing employees of utilities to work without separate licensing and permitting was based on a model of companies that had a cadre of lifetime employees and a regimen of clearly defined procedures. That model fell apart in the late 80s and 90s when these employees were laid off and rehired as "contractors". Once they retired we have new contractors entering the trade with no particular background in this arena.
I guess the real question, going forward, would be how would building departments like to handle things like telephone, cable and satellite installs? Do we even have a good idea of how many are going on now? What kind of fees would you charge? I am sure there will be a lot of resistance from the various companies and the customers if they have to add $50-100 to their installation prices.

This statute doesn't have anything to do with permitting. The AHJ's can set whatever permit fee they want to. For most I guess it would be the minimum permit fee for electrical.

Nick, my point is most of this work has been done without any permitting or inspection. If you start parsing the language to require every satellite installer (not cable installer) to be licensed and pull a permit the effect will be chilling on the industry. It will certainly limit the "free installation" deals.
I also doubt most people have seen an "employee" phone installer in years.

I believe that a permit is already required under 553, Florida Building Code.

If you told that to the trunk slammer who put in my Dish last month he would have cocked his head like a puppy and said "¿que?"

I have a very good question this exemption 14 (a) what types of companies is the meant for? Utilities or any company that opens a shop installing cable/coax or Cat5e wiring for Data/Phone?

Also would it cover work subcontracted out to independant contractors not employees?