Dear Throbber - you ask "why, why,why?" How do you propose to avoid a "private aircraft" from entering USA airspace and impaling itself in a building somewhere?
THAT IS WHY.
Overreaction by US officials? Probably. But until a solution shows up, the US government is erring on the side of safety and stepping on our "human fights." Unfortunately, we are going to have to give up some of those until solutions are found. So how about proposing a answer to the problem rather than just complaining?
As far as AMBULANCE DRIVER PA38 (see profile) is concerned - I, as an American, greately resent your off the wall assertions and comments.
I thought this was a forum for aviation professionals.
Flying Guy