The Latics fell 3-1 at home to the Rams this afternoon, prompting a chorus of boos at the DW Stadium.
"It's hard to take, it's been a horrible week," the Scot, who joined the club in the summer, told reporters. "We lost our first game at home last week and it's a week that should have led to a lot more promise than what we've delivered."
He added: "If people want to be ultra critical, that's the nature of football these days. I'm old enough to deal with that.
"If they think there's something better that's all well and good. That's why we love football, it's all opinion."
Wigan are 14th in the Championship.