The team and the fans should face it. Betis could've won that game easily after a very good first half. They had two counterattacks dismantled by Diego López and a header that hit the crossbar off a corner-kick. Yes, Real Madrid improved a lot in the second half and probably deserved to win the game, but Ancelotti's men were lucky to get the three points.
Marcelo is getting a lot of praise for his offensive performance. He played well when the team had the ball, but Betis counterattacked through his wing and the Brazilian midfielder never helped Ramos or Modric. Marcelo still needs to get back to his 2010-2011 form, when he was also a dominant force in defense. Ramos' terrible performance could've been much better if Marcelo had helped him.
Carvajal looked quite nervous to me. He never contributed as much as in preseason games when Real Madrid had the ball, even though he had an easy line to the goal most of the time. Real Madrid were attacking through the left side of the pitch, and Carvajal should've tried to make profit from that. Furthermore, he struggled defensively as well against Cedrick's pace. Khedira and Pepe had to cover his back many times, and luckily enough for Madrid they succeeded. Carvajal still needs to improve a lot if he wants to get that starting spot from Arbeloa.
It was shocking to see Cristiano Ronaldo play that much as a winger. Whether that was Ancelotti's commands or not, the Portuguese player tried to receive the ball in that wing. He didn't have an easy game against Betis' offside defense. Cristiano Ronaldo should've probably tried to open up more space in that left wing by moving to a much more centered position, because Isco, Marcelo and even Modric were playing through that left wing. That might be why Ancelotti decided to change Isco and Özil's positions in the second half. Özil (who didn't have a good game) moved to the left wing and Isco went to the right trying to open up more space in the wings.
Casemiro successfully replaced Sami Khedira after the German player had to leave the game with an injury. Khedira struggled quite a lot in that defensive midfielder position. He doesn't need to press the opposition that much when he plays there, and Casemiro understood his role much better.
On a final note, Benzema clearly needs to improve. He scored Real's first goal but he blew off two or three scoring chances that he should've scored easily. Him and Ramos are the two players that need to step it up for the game against Granada.