As others have said it is primarily a "show of force" to justify their existence.

As I said a bunch of times, when I was "disobeying them" my main concern was not arrest but a huge misunderstanding. The TSA's got *really agitated* and were following me and trying to get in my way, so I was worried about some "hero" passenger coming on the scene and tackling me (Flight 93 fought back!!!), or a cop coming over, and a TSA pointing vigorously to me, and the cop not understanding the situation and drawing his gun or something, thinking I sneaked past the checkpoint or was doing something actually suspicious.

I wanted to reach into my bag and get my camera but I dared not do that for obvious reasons once they really escalated the situation (again, I really didn't think the TSAH's would get so agitated.)

Secondly, I don't think they ever called the cops despite all their "threats" and me calling their bluff requesting a cop. As soon as the drill ended I saw several cops 100 feet away around the bend at a substation, who didn't even look at me. The TSA's didn't go in that direction. I wouldn't worry about it too much.

I'm a middle aged cardiologist, all of the TSA agents appeared in their 20's in this case... Other people in different backgrounds / appearances might not be so lucky.

You will also turn yourself into an actor in the security theater -- with everybody else freezing, at least a couple dozen people were watching the TSA's yell at me. Most people looked kind of amused at the whole ordeal, but you might get a few pax also yelling at you, "HE SAID STOP, WHY DON'T YOU STOP SO WE CAN ALL GO" and that type attitude. Didn't happen to me though.