Not acceptable but not really a surprise.
In 2002 taking an Easyjet flight from CDG to LTN there was problems with the bags and anybody with bags had to get off and identify their bag before it was loaded.
One ex colleague who was also travelling couldn't find her bag and clearly a few other flights had same problem as eventually her bag was found with other bags ready to be loaded to Lagos, Nigeria. Plane left about 2 hours late.
A US friend stood in line behind a woman who was demanding an upgrade and really harassing and abusing the checkin clerk as she said she was a frequent flier who flew once a year. Eventually when got nowhere screamed well I hope this ticket is for Miami, clerk smiled and said yes and woman walked off and he heard clerk saying very quietly your f*****g bags are going to Bogota.