Because the judges don't trust us to make the decision so they want first dibs on who goes, then when they can'tt decide they throw it back to us again.
Seriously though, it's not always been this bad. This is the first series where it seems to go to deadlock every week. In previous series they've usually made their mind up. Simon usually has good reasons for taking it to deadlock. Cheryl on the other hand... "i don't want to chose, take it to deadlock"