The OP implores us to "Just stop and think for one second" and discusses the jetBlue terminal clearance due to the fake grenade.

I have no issues with the TSA stopping fake grenades. I do think that if anyone at the TSA were to Just stop and think for one second, they might have concluded that emptying the entire terminal was not warranted. Emptying the entire terminal and re-screening everyone was a tremendous waste of time and money.

There's simply no reason that a grenade (even if real) at a checkpoint (don't know if it was carryon or checked bag) calls for emptying the entire terminal. If it blew up it simply wouldn't harm anyone more than x feet away. If anything, it places the passengers at greater risk of a secondary attack at the curb. Everyone who has studied terrorist behaviour know this. Anyone for whom "risk management" is a familar term know this.

So clear a safe perimeter. But emptying an entire airport terminal? All you've done is tell the terrorists that they can make everyone dance and spend $$$ by showing up at the airport with fake grenades in checked bags. Sorta the dimbulb nonsense of taking every phoned-in bomb threat seriously, like it was the real thing. Terrorists in the USA don't phone in bomb threats. When idiots are in charge of security, we don't get security.

OP: Just stop and think for one second, please.