Pressured by Jewish leaders... crucifixions were ordinary then?
He wanted to be remembered as the good guy...
Probably the sh it he was saying made pilot sick to.
Pressure from the pharisees
Jesus was rousing ethnocentric sentiments in some of the segments of Jewish society. This was seen as a threat to stability in the region. The local authorities agreed with their Roman counterparts and elected to eliminate Jesus as a way to quell these sentiments before they could reach a boiling point. Jesus was aware of this, and as a result tempered his message into a less aggressive form. This upset some of his original, hardline followers, and led Judas to testify to the state against Jesus as retribution. Now having plausible evidence from Judas's testimony against Jesus, they executed him.
Because there would have been a riot if he didn't.