Astrologers' predictions fail to impress

The recent furore about Professor Brian Cox and Dara O'Briain being suitably honest and straight-forward about astrology leads me to ask a question.

Why couldn't the astrologers predict the occurrence and get their complaint in before it actually happened?  

That really would have been impressive.

See the article in The Guardian.

 . . . Dara was explaining that all of the planets orbit at different speeds and distances away from the Sun. He said only the earth orbits the Sun in 365 days and returns to its own place, showing that horoscopes are nonsense. He then went on to add "Let's get this straight once and for all, Astrology is rubbish" The other presenter, Brian Cox, then agreed and said "in the interests of balance on the BBC, yes astrology is nonsense."