He won it because he was vocal and supportive of his team mates. He didn't win it for banging in many goals. He is a captain and he did what a captain needed to do when it mattered, and that is take ownership of his team mates motivation.
My hypthesis is this: Ronaldo wants attention more than anything in the world.
With that in mind everything he does makes sense: Trying to be Dinho at united, Knowing exatly when cameras are on him with the faces and gestures, weird free kick stance to stand out, weird celebrations to stand out, introducing a chant after a goal, celebrating alone while the rest of the team celebrates with the goalie that just saved your cl and future ballon d'or by correcting your mistake, not celebrating teammates goals etc, taking off your shirt of to show your abs all the time depsite being a diver etc.
On a positive note its many goals and hard work, gets you most attention and can help you keep it up for years.
Ballon d'or is the ultimate attention for one person trophy you can win in a team sport. In my opinion also the award he values the most.
Him, Mendes, Flo made the whole thing about goalscoring since he cant compete with Messi otherwise. Think about, before it was never about goals, it was about the best player or best player in a team that won biggest tropies. It was flawed but youd never expect an Inzaghi to win it.
So logically a declining player like him becomes the ultimate poacher. That way he can score 1/2 goals, play shit 90 minutes and nobody will remember it. "Yeah he scored 60 goals, youre a hater if you think he sucked"!
stats bring attention and erase memories, pr brings attention, shitload of people endorsing you in Madrid media helps. Waiting to take the last penalty to snatch all the glory in a cl final helps despite it backfiring at ec 2012.
Milking an injury for the camera and pretending to be coach to take the attention to you rather than the rest of the team playing also helps as seen in your comment.
Shitload of people who have bad memories and remember "him leading them to glory"