I'm sorry but to the naysayers,
what kind of ending were you expecting, exactly?
Obviously they had to reason -A's motives without just saying that she was crazy. CeCe became insane from years of neglect from her family and medication and she clearly became attached to being part of the family so she started '''dating''' Jason to get close to them. It's a very solid ending albeit the random timeline blunders (still wtf @ Bethany killing Marion when she was literally a toddler & Shower Harvey being BW/RC

)
Kinda hate how they didn't even tie in CeCe being kicked out from UPenn. That was her way of living a normal life and she felt the Liars took it away from her so she became vengeful.
At the end of the day, the top two A contenders were Wren and CeCe, either way who was revealed, it would have legit been the exact same storyline sans the transgender angle, which, by the way, was a nice change from the usual PLL relationship scenes, etc.