Why Astrologers go wrong in their prediction?

• Lack of knowledge: This is perhaps the foremost reason. Most of the astrologers, after learning a bit, find it difficult to resist the temptation to start making predictions. A certain percentage of their predictions do turn out to be true since they have learnt a little bit of Astrology  after all. They cannot hold themselves back from showing off their half baked knowledge. Another reason if the temptation to start reaping, as soon as possible, the fruits of their efforts made in learning the subject. Once the customers start flocking to them, they lose the urge to keep learning further. Also, they are left with little spare time to make further efforts to learn more. They get too busy duping people.
• Lack of Talent:  In the modern times, since the pursuit of this subject is not considered very respectable, persons of genius do not take up the study of Astrology. They would rather prefer to become scientists, engineers, doctors, litterateurs, artists etc. This does not help the development of Astrology nor does it help add to the knowledge or find the missing links in this subject. Currently, there are no serious research projects related to this field. Thus this base of knowledge does not get updated.
• Incorrect Data: As the very basis of Astrology is mathematical, the data such as time of birth etc. must be accurate. If this data is incorrect, the horoscope and consequently the interpretation of it is bound to be faulty. The position of cusps, house divisions, and the planetary positions at any given moment needs to be accurate too. The numerous ephemeris  differ from each other so much that it seems incredible. One must follow the most accurate data (for example, from NASA) for calculations, in this age of science. Normally, astrologers tend to take the easy route, that of following some ready-reckoner sort of things, leading to inaccuracies in their calculations.
• Destiny of the subject: It may so happen that the fate of the person who wants his future read, does not favor the person in knowing his future. This idea may seem far fetched but it is not. Even in modern times, with all the development of medical science, patients keep dying of fully treatable diseases. If a person is destined to die of pneumonia, he will in spite of the fact that millions of people around the world are successfully treated for it every year. If fate can play a role here why cannot it play the same role regarding Astrology.
• The very nature of Future: Modern science divides the universe in two parts: known and the unknown. It is believed that whatever is unknown today, will become known tomorrow. Over a period of time, every thing will become known one day. But the enlightened sages have said that certain aspects of the existence is unknowable. These things do not belong in the domain of human knowledge. Certain aspects of future also belongs to the same domain.