The issue is that that dirt and rocks flying around damages all the other expensive equipment at the launch site. There is going to be some very dead kit down there. They can't do that every time.
But big dust clouds also upset people, and SpaceX can't afford to fall out with the locals.
I was on South Padre Island watching the launch, and I was stuck in traffic on South Padre Island for almost an hour afterwards, and I did not observe this.
It’s possible that some of the dust reached South Padre or Port Isabel, but neither seemed to be “covered” in it.
I mean the concrete dust that got airborne as it was being blown apart. It's airborne silica and is toxic which is why construction workers wear masks when producing it.
But big dust clouds also upset people, and SpaceX can't afford to fall out with the locals.