Why intelligent people fail?

If children grew up according to early indications, we should have nothing but geniuses. --- Johann Wolfgang von Goethe

Sternberg in his book argues that the traditional notion of intelligence should be redefined to include successes. He lists some of the reasons why people who are generally thought of as intelligent fail:

Lack of motivation

A talent is irrelevant if a person is not motivated to use it. It is better to be motivated by personal internal goals, rather than external motivation like social acceptance. Motivation based on external factors is unreliable, transient, while internal sources are normally more consistent.

Lack of impulse control:

Habitual impulsiveness gets in the way of good decisions or actions. This can lead to not bringing their full intellectual resources to bear on a problem but go with the first solution that pops into their heads.

Lack of perseverance and perseveration

Some people give up too easily, while others are unable to stop even when the quest will clearly be fruitless.

Using the wrong abilities

People may not be using the right abilities for the tasks in which they are engaged.

Inability to translate thought into action:

Some people seem buried in thought. They have good ideas but rarely seem able to do anything about them.

Lack of product orientation:

Some people seem more concerned about the process than the result of activity.

Inability to complete tasks:

For some people nothing ever draws to a close. Perhaps it’s fear of what they would do next or fear of becoming hopelessly enmeshed in detail.

Failure to initiate:

Still others are unwilling or unable to initiate a project. It may be indecision or fear of commitment.

Fear of failure:

People may not reach peak performance because they avoid the really important challenges in life.

Procrastination:

Some people are unable to act without pressure. They may also look for little things to do in order to put off the big ones.

Misattribution of blame:

Some people always blame themselves for even the slightest mishap. Some always blame others.

Excessive self-pity:

Some people spend more time feeling sorry for themselves than expending the effort necessary to overcome the problem.

Excessive dependency:

Some people expect others to do for them what they ought to be doing themselves.

Wallowing in personal difficulties:

Some people let their personal difficulties interfere grossly with their work. During the course of life, one can expect some real joys and some real sorrows. Maintaining a proper perspective is often difficult.

Distractibility and lack of concentration:

Even some very intelligent people have very short attention spans.

Spreading oneself too think or too thick:

Undertaking too many activities may result in none being completed on time. Undertaking too few can also result in missed opportunities and reduced levels of accomplishment.

Inability to delay gratification:

Some people reward themselves and are rewarded by others for finishing small tasks, while avoiding bigger tasks that would earn them larger rewards.

Inability to see the forest for the trees:

Some people become obsessed with details and are either unwilling or unable to see or deal with the larger picture in the projects they undertake.

Lack of balance :

Lack of balance between critical, analytical thinking and creative, synthetic thinking. It is important for people to learn what kind of thinking is expected of them in each situation.

Too little or too much self-confidence

Lack of confidence can make failure a self-fulfilling prophecy. Whereas too much confidence can mean that critism is taken badly and there's no room for self improvement.

Update
The Apollo Syndrome also describes why some intelligent teams might fail.