I'm not a fan of it either. Just sayin' that concerts and events are where the densest crowds are. Are we protecting people from doing things to events more than the events themselves? I'd hope this is an argument for more granular control. I'd love to fly short-hops without ID, but maybe TSwift concerts should require something? (Edit: Do they? Events/venues do start to have their own security at some point. Flights also have different controls for national vs international.)
I'm also probably overly discounting border control. Traceability in particular. I'm not a fan of this either.