I agree! Being subjected to cheesy piano bar renditions and Johnny Mathis vaseline vocals of "Let it Snow!" "Walkin' in a Winter Wonderland" "Sleigh Ride" "Jingle Bell Rock" "You Better Watch Out" and "Chestnuts Roasting" for hours on end is enough to make even Bob Cratchet want to go out and seriously hurt someone.
I'll bet that the increased crowds also irk these salespeople but that wouldn't make a good bargaining point for the Union... "I want you to post someone at the door and only allow 2 customers in the shop at a time!".