I think the disruption is at or above the elevation shown in the various zones. Which means hiking in Florida shouldn't be affected. I've never been there, but I don't think there are any 10,000 foot mountains.
On the other hand, on the West Coast diagram, you can see that one could easily be hiking above the service ceiling of quite a few small general aviation aircraft.
Why is this this happening?. I suspect it has something to do with denying exact geographical information to our enemies, while retaining the facility for our own military. Note that the US launched a heavy (20 tons, size of a city bus) secret military payload from Vandenberg on Thursday