I disagree.

When yo go to a Hospital Emergency Room, Is it first come- first serve? No. Of course not. Similarly an airport check in line is not a line at your local Bakery.

What happens when AA has to "reaccomodate" the Paxs who missed Chicago flight? It wrecks havoc in the system.

Where's the harm? The paxs who "cut" you made their flight as did you yours. Admittedly a small minority abuse this system, but Paxs still need to be prioritized based on departure time. Air travel is time sensitive, not merely first come first serve.