It is not the low voltage work, but the electrical changes that accompany the integration process and the load calc's to circuits you change in the process.
If as an integrator I just added a 40 va transformer to a circuit, that's no big thing.
But when I add a load of equipment plugs, transformers, power supplies to a circuit say 20 amp and i am just a low voltage guy. Then I set up a circumstance or situation for a meltdown or potential electrical fire'
The little Dvr, Nvr is not the reason for the license . It is the circuit changes, additions , to panels , and equipment completed by the integrator.
How often do you go to install a cctv system and the panels electrical system is full, maxed out.
You have added a 4 amp nvr , a 1 amp switch , wifi hub , encoders, decoders , power conditioning equipment .
Non licensed personnel are not usually from an electrical background and don't know not to just keep adding plugs, receptacles, outlets that just cause fires .
When you exceed the max in a panel or wire or undersize the wires or transformers you cause heat loading and set up for a future fire .
How often have you gone into a closet or closed area and felt the extreme heat load with no ventilation or Hot transformers?
This is Why!
As An industry expert with over 35 years experience in integration, I have seen it all!
ungrounded, unbonded, outright safety violations, and worse!
Licensing keeps us to a standard of excellence!