Although this blog post is a few years old, I'd like to shed a little light onto why boarding passes haven't changed in years.

To redesign the boarding pass, you have to understand how the data is processed and presented. Often the terminals and printers are shared between airlines, so there has to be a standard.

Each airline uses something called a PECTAB. This a basically a template that has coordinates of where the data is to be printed (text & logo). It's loaded on the printer each time the airline terminal application (such as Sabre, Amadeaus, etc.) connects to the CUTE (Common Use Terminal Emulator, IATA standard) API hosted on the computer which acts as a gateway to the printers, OCR scanner, etc. Did I mention this is a shared terminal by several airlines that have completely different applications? :)

A lot of the BTP (boarding pass) printers either use the older dot style printing, but the newer thermal (GPP) printers are becoming more common because they are cheaper to maintain.

Unfortunately, the terminal emulators and CUTE standard hasn't kept up to date with the available technology, a lot airlines are still running on mainframes from 25+ years ago.