You can stand with your back to the sea and shoot fish in a barrel, but you ignoring the giant shark which eat people and boats.Okay, Confucius wasn't around at the time when Jaws graced the big screen. But if he was and he worked on technology projects then he would have said something like that. Probably.
What this pearl of wisdom means in real terms is this. If you are working on a big project and you need to reduce timescales, axing the simple stuff is not only ineffectual but will ultimately be to the detriment of whatever you produce.