That's dope! Do you have any idea how many times I've chosen to risk not taping cords down, simply because I didn't have time for it?
In many cases it's actually safer to
not tape down cables, as long as you 'run it clean' as they say and ensure you minimize hazards!
I don't personally think I've ever worked on a set where cables were taped down in the way that this gadget does it. Usually it's the green Best Boy identified by the cables he keeps taping down, often shortly followed by the Gaffer coming through and saying 'who the hell keeps taping down my cables?!'
You might use safety mats, or run the cables in areas that
aren't walkways - keeping to walls , and out of the way as much as possible. Sometimes you may use tape if the cable is in a precarious position, but as a general rule you rarely see long cable runs taped down like that.
Gaffers are hired not just for their creative knowledge of lighting - indeed, most DPs generally should have quite a good idea of how they want to light their scenes, and would be able to
manage Gaffer-less if it really came down to it (assuming the appropriate equipment was hired).
The Gaffer, however, should be knowledgable about electricity, the hazards associated with it and how to safely rig lighting to get the effect the DP wants in a safe manner. Some Gaffers I know and have worked with have indeed been licensed electricians in the past.
That's why you have such segmented and compartmented departments on a film set - the lighting team should all have sufficient training in lighting so as to keep people and lights from breaking, whilst still getting the right effect for the DP. That's why your lighting team will get snooty if the AC starts trying to move a light - the AC has the best of intentions but he likely doesn't have the same experience and training and (though unlikely) is potentially endangering the people or equipment around him/her. Even if the AC comes from a lighting background, he/she doesn't know the intricacies of the current cable run for the set.
Realistically, there are generally way too many lights, way too many cables, and not enough time to tape down cables in that fashion - and sometimes when there are that many cables, it can be more dangerous to tape them than to not! In any case, the lights are often moving around so often that taping their cables down, and having to rip up and then re-tape cables every time you move a light (which in many cases can be every shot or even between takes!) is ridiculous and way too time consuming.
Of course there are times when I've seen cables taped - if they're in a precarious position (say running along a wall or over a doorway) - but you're more likely to see cables running through or over clamps than being taped down.
Of course, if you're in a public space and are running long lengths of cable across walkways, and are going to have such cables in place for extended periods of time it's a different story and of course if you, as the head of department
want to tape your cables because you feel it's safer, that's entirely your call. Generally though, I would rather use mats.
As always,
your own personal situation will be different to others - I will take no responsibility for injuries caused in your own situations

(plus I don't think 'some guy on the internet said I shouldn't tape down cables' is a legal defense..), and I'm not saying you should
never tape your cables, just that in my experience it is very rare.
The more experienced crew you have, the more confident you'll likely feel when they
don't rip out their Gaffer and start taping their cables down.
I imagine this would be great for those doing live or event-type stuff, particularly audio.