I do not believe in astrology. And I discount what people have to say on other things if they say they do believe in astrology. Because if they believe in this irrationality - even after being explained how astrology is bunk - means they are unable to rationally account for other stuff as well. Even if someone believes in astrology and say they believe in evolution as well, means they believe in evolution on shaky ground, i.e. by chance, and not because they have a firm understanding what evolution is. If someone, that does know how a scientific discipline is put together, then they also could apply a similar rationality on astrology and reason that it made no sense.
"The first principle is that you must not fool yourself — and you are the easiest person to fool." - Richard P. Feynman