Other people read the good reviews and determine to make their decision from that.
I read the bad reviews. 1 to 3 star reviews. I'd rather go to a place with a bifrication of bad and good reviews where the bad reviews are stuff I don't care about...
My theory is that if a place sucks it will definitely have bad reviews. A place that is great will still have a few, but they will be over stupid stuff (i.e. I expected something different etc.)