Some of us have come from families in which we got very little attention or positive feedback and it has been a big step to learn to praise our children. Praise can imply a judgment. Praise is often conditional. Praise focuses on the end result. The struggle, the falling down, the mistakes, the hard work leading up to the achievement are not acknowledged nearly as much.
Praise is often inaccurate.
Praise that is not descriptive of what the child is actually doing can convey to children that we're really not paying close attention. Praise emphasizes external validation over internal feelings of satisfaction. Children who have grown accustomed to praise can lose touch with the inherent feelings of accomplishment that come with their achievements. To this day, I want outside acknowledgment for every task, no matter how trivial. Praise can lead to competition.