There are two reasons for this. The first is that we've become an unreasonably safety-conscious society, driven, at least in the U.S., by the litigious nature of our society. If something can cause harm, however slight, it must be banned.
eli's dog may have disagreed (RIP)

Now with my moderator's hat on:
Caution - Debating the merits or problems with a safety oriented society or the roles of litigation and government in such things is definitely political and off topic on this photography site.
So let's not go there, unless it has a specific to photography component.
Moderator's hat off.