I have flown twice in the past few years without ID when I misplaced my wallet. TSA made me sign a form which basically said nothing useful. Children fly without ID. It's about control not about flight safety.
The comment you are replying to didn't say anything about safety, merely disruption, and I'd wager having a ridiculously large number of people going through extra checks and having to sign forms would be super disruptive ;P.
I have flown twice in the past few years without ID when I misplaced my wallet. TSA made me sign a form which basically said nothing useful. Children fly without ID. It's about control not about flight safety.