No the installer is a dangerous idiot. The important part is 810.21(F) which lists where you can connect that wire. Of the things listed a "random light switch" is NOT one of them.

Two grounds are needed--one from the antenna mast (nearer the bottom is fine) and one from a grounding block on the coax. Those grounds ideally should be #6 and run as directly and as much in a straight line as possible to the grounding point for your electrical service.
From a practical perspective, longer runs, smaller wire and more changes in direction are still (maybe) better than nothing.

Here is a link that might be useful: Grounding bridge

Thanks, both. I had sent him an email to come out and rework it, but I think he doesn't understand the issue even as much as I do, and that's a very small amount. I'll hire someone who does and eat the cost rather than let him mess with it. (FWIW, I started being suspicious of him when he didn't know to loop the co-ax so that water would drip off outside rather than run into the house. When I started looking, I started finding things that made me nervous.)

Do you use dilectric grease on the antenna ground wire join?