Sure, it's bullshit, but sometimes the generalizations are suspiciously accurate.
I am a Virgo. Most people say that we are thoroughly dependable, detail-oriented, neat and typically even-tempered though somewhat intractable. Several women have told me that Virgo men are the most attractive by Zodiac sign.
In my experience, Scorpions have magnetic personalities but tend to be untrustworthy. The majority of male Scorpios I've been friends with have been traditional "players": never had trouble lining up women, never had trouble convincing them to come back, frequently cheating on them.
Pisces are huge day-dreamers, typically cool people, extremely unmotivated. I have known so many Pisces who were smart, funny, had great ideas but zero follow-through. My doorman is a Pisces and he's a smart, funny, college educated guy, but almost everyone who comes to visit us comments on how flaky he seems when they first meet him.