This is insane. A major purpose of the gate ticket reader is to check the passengers and to ensure that people are boarding for the right flight, that no seat is doubly assigned, etc.

I also believe that UA made a poor purchase with these machines. The UA machines are mechanical and break frequently. Delta purchased machines with an optical reader that scans a barcode; these have no moving parts and are much less likely to require repairs.

Of course, you could take the Southwest low-tech approach with color-coded, plastic cards. This is the simple and elegant solution to a complex problem.