But the former England captain has come out fighting - insisting that his mis-firing forwards should shoulder responsibility.
James Beattie missed a penalty kick awarded for a foul on former Scunthorpe striker Billy Sharp, while Chris Armstrong and Lee Hendrie both missed clear chances.
"I can understand the fans' frustration but what I can't understand is when a player misses a chance and they criticise the manager," Robson said.
"As I've always said to the supporters, 'give me time and patience'. "I've had criticism since I first came in here but you can't turn things around and achieve what you want to over night.
"We've created enough chances to win three games never mind one. They weren't even chances, they were sitters. The effort was there and the work-rate was there but we lacked that bit of guile to finish them off."