The real problem is that once again someone treated what should simply be an identifier to look up data as something more. Why not store all this information on the server that an authorized person can see when they scan a uuid on the boarding pass? Would they allow boarding of the network was down?
There are procedures in place in case the network is down. I have flown with hand-written boarding passes multiple times in the past (they even had special cards for that situation laying around). On the other hand there were flights that were grounded as there was some network malfunction. I guess it depends on the specific problem they have.
Can you imagine how slow boarding might be if the information needed retrieved from a distant mainframe by the scanner before it would emit its _beep_ of consent? (I agree with you, though)