If astrology was true, why aren't the astrologers the most successful people?
You have presumed that astrology will make someone to be successful without any effort. Thinking astrology as a magical tool to achieve success in life is no more than ignorance. Think about following scenarios,
If modern medicine is flawless then why doctors get disease?
If priest in temple takes care of daily rituals of god then why they can’t magically get anything?
If teachers would know answers to every question, then why don’t they go and clear all the tough exams in the country?
In all the above scenario, people are doing service. Doctors have compassion for patients, teachers have great intention for their students success and astrologer have great wisdom to help people to understand their karma.
Secondly do you think successful is all about acquiring material things?
If having wealth is the ultimate success in life then why suicidal incidents happen for billionaires.
In my personal experience, anyone who practices astrology(with right spirit) will have strong Jupiter which is the planet of wisdom. A good astrologer will always have great wisdom of life, they will be matured enough to differentiate material success and content that comes through compassion and caring.
There are few unethical astrologer who may be making lot of money by cheating common people, which is true in any other profession like doctors who fears his patients, teachers who abuses his students etc.
So In summary, astrology is not magical tool to get success with short cuts and it is never meant to be. Astrology is a wonder tool to understand our past karma, so that we can alter our present act to create beautiful future and the true astrologer would help their client to identify the same.