Perhaps because they're security conscious zones and often have heavily armed officers present?
http://www.usatoday.com/story/news/nation/2015/03/21/new-orl...
I don't think the TSA agents should be armed, but I'm sure everyone (even the TSA agents) were happy deputy Slyve was.
The only way you can do that is by completely uprooting society. Any idiot can take a machete to the airport or a schoolyard or any other place where there are a lot of people and act out their ill fantasies.
An airport is actually a really stupid choice exactly because there are a ton of armed officers floating around.
Suicide-by-police officer is a pretty good description of acts like these.
I actually find it irresponsible to fire a weapon in a crowded security line. Two innocent people were shot.