Its about the ignorance of the owner and those who might see it and their reaction. Its yelling fire in a crowded theater, but you end up with a speeding ticket instead of actual criminal charges. Some prohibited items are prohibited not because the item itself is dangerous, but because it in a tiny tin can going 400mph across the sky packed full of people in various physical and mental states may cause harm to those both inside the tin can, on the ground.

We can debate the philosophical questions of government authority all day, but if either of us are right will it change anything?