Why is there so much precasting?

> Don't deny it doesn't happen. How many times have I seen more> than three times the necessary people audition and many people who> deserve the part to see one of the director's relatives (wife/husband,> daughter/son, brother/sister and so on) get the part, despite the> fact their audition was actually inferior. And it's not because they> the right "look" either. Why bother auditioning the part> if the casting is a foregone conclusion? Is it just for show?Sometimes yes.I condone this not, but I reckon it's because directors often dream of particular performers in particular roles, and being the morbidly obsessive creatures that they are, will let nothing stop them from achieving their wishes, lest the world put another chip on their sloping shoulders.Any other brainstorms?