To follow left rudder, I believe that it is essential that an airport have a fast-track *process* but agree that it shouldn't be a vended option, but should be reserved for urgent situations.
For example I was once fast-tracked at City after the oversized-baggage guys took nearly 30 minutes to process my already-disassembled-and-bagged bicycle for a BA flight. I was in jeopardy of missing boarding, so I was sent through ASAP.