It culls out lousy prospects like ME.
Obviously if a telemarketer calls me, they are wasting their time.
Better to move on to some brain dead idiot who is so lonely they will talk to anybody.
I've seen these people in front of a congressional committee whining about how they got taken for the THIRD time, "cause they thought they had just got the "deal of the century".
Amazingly, I got called out of the shower three times in two weeks.