Goals from Scott Malone and Wes Thomas gave the Cherries a comfortable 2-0 win at Dean Court, with Scunthorpe manager Knill disappointed at his side's performance.
"At times there was clearly a lack of thought and I’d expect the more experienced boys to step up and help the younger lads along," said Knill
“It’s really difficult to take. They’ve had three shots on goal and scored twice and they were both really poor goals to concede. At the moment it’s like we are taking two steps forward and one back.
“Let’s be honest they have been some pretty poor performances. You want your players to be enthusiastic and show plenty of energy but I just didn’t get that.”
Lee Bradbury, the Bournemouth boss, praised his side's work commitment.
“The guys put in a really good shift. We proved that when we’ve got the got the ball we have the quality," he said.
"I thought we played fantastically well and a victory like this will help breed confidence. We are on a little run of results now and we just have to keep it up.”