Because it has lost all its appeal after the A reveal. Some spoilers included.
  1. Spencer is actually a high dollar escort in DC and not a lobbyist. That is how Caleb actually reconnected with her.
  2. Ezra Fitz's new love interest was actually kidnapped and killed by Joran Van Der Sloot in South America.
  3. Emily dropped out of Pepperdine and she becomes the eye candy El Chapo seeks. So she begins getting secret texts from him which leads to Sean Penn meeting the drug lord. So El Chapo is actually A and not CeCe.
  4. One of the liars is killed. Preferably by another liar.
  5. Sara Harvey is not handicapped due to the electric shocks experienced in A's doll house. Instead, the shocks changes her personality forever and she becomes Joker's love interest Harley Quinn.
  6. Spencer's mom is actually Olivia Benson from Law and Order. That is why she is always never around.
  7. Even ABC realizes PLL has run its course but still has 1.5 seasons left in contract so they decide to change the name of ABC family to Free Form. They do this so they can start airing Hannibal Season 4 in Rosewood and hope everyone forgets about Pretty Little Liars .