The longer we can go without a goal the better the defense well feel. Also, it takes the pressure off the forwards, as they know they won't need to score 2 goals just to draw, for example...
I'm fairly surprised by our start to the season but astonished we haven't conceded a league goal in the last 5 1/2 hours of football. I certainly didn't forsee that.
The moment we sit back is the moment we invite pressure. The current tactic seems to work, so let's not change it. No unnecessary risks or anything, but keep them under pressure.