So you think people should be able to just waltz right onto an airplane without identification? Someone could easily just have their ticket purchased by someone else, use that ticket, and get on the airplane, which would be a security risk. It helps you by helping you not have someone who stole your ticket get on the plane in your place. And how do you expect age restrictions to be enforced without ID? Some people look a lot older or younger than they are.

Yes, I think people should be able to just waltz right onto an airplane without identification. It works great for trains, why not planes? I don't see how the scenario you outlined is a security risk. There are plenty of other, better ways to make stolen tickets unusable.

How do I expect age restrictions to be enforced without ID? I don't. The US's age restrictions on alcohol are stupid and should go away.

Edit: actually, I don't see how the current regime prevents using stolen tickets in the first place. IDs are only checked at security, not when boarding. So you print out a fake boarding pass with your real name and use it to get past security, then use your stolen ticket to board the plane, where they make no effort to ensure that you are the person listed on the boarding pass you present. Easy! Well, until the real passenger shows up with a reprinted boarding pass and wonders why you're in their seat, at which point you get hauled off to jail.

Yes, I think people should be able to get on an airplane without identification. It is a perfect example of a bogus security check which causes hassle for everyone without materially impeding anyone who wants to cause problems.