The problem is goals often produce undesired, unexpected, and unanticipated results. Look at the mess and cheating scandal in the Washington D.C. school system, where it has been discovered that teachers systematically improved their students standardized test scores by erasing incorrect answers and writing in correct ones. They were threatened with being fired if their students underperformed and not surprisingly, when they discovered they could not raise the test scores fast enough, resorted to cheating.
This shouldn't be a surprise. Anyone who has lived through enough challenges in life knows that people will resort to nearly anything when threatened with the loss of their lives, their possessions, or even their jobs. In fact for many people, those three things are wound up like the Gordian Knot.
So don't be surprised when you set goals for another person and then pressure them to do it, that quality goes down or is faked to get the desired results.
Sometimes pressure doesn't make diamonds, it just gives you crushed coal.