Well, you're not wrong that it can be used invasively, just as a gun can be used to kill instead of used for target practice on a tin can. But only one of those uses of a gun would count as a violation of the Laws ... the same could be said of thought transmission, in that light.
I get where you're coming from. I guess it's kind of like that mind control law. Sure, you
can use mind control to get a date with a supermodel, but you could also use mind control to help your pregnant friend kick heroin. Surely that would be a good reason to use mind control, right.
Leaving the offensive stuff behind for a minute. Forget about offending, scaring or confusing a defenseless mortal for kicks. There is still the inconvenience issue, and I don't think there's a work around. Call display is a Godsend, and it allows me to not answer my phone more than I answer it. If I really want to dig into a book or something, I'll unplug the phone and turn off the cell. Come to think of it, Harry unplugs the phone when he's doing big magic too.
So imagine someone who really wants to get into a book, or a doctor who is in the middle of open heart surgery, or a wizard who is so focussed on a delicate magic ritual that he can't spare even a little focus on a call block. Then just at the critical moment, he gets a brain wave. "Hey, we're going to Mac's. Meet us there".
A bit melodramatic, but it's still an invasion of privacy.