Biblical question: why is Judas Iscariot viewed so negatively, yet his actions were necessary?

Most people know the story of Judas the betrayer. The word “Judas” has come to be a general term referring to a betrayer. Judas Iscariot is almost universally viewed as a negative menacing character in the Bible who betrayed Jesus for money and his motives are weak and ill-defined. Yet at the same time, Jesus knew that someone would betray him and that his fate was ultimately to die. Jesus’ death is obviously an important event in Christianity; without it there would be no salvation through Jesus. Judas played an important role in something that needed to happen and yet he is vilified for it.

Obviously there is a lot more to the image of Judas. His name just means “Jew” and he is associated with Jews as a whole. In Matthew 27:25, the Jews proclaim their guilt for the death of Jesus. Judas was often a symbol of the menacing traitorous Jesus-killing Jew and was used in support of anti-Semitism for centuries.

Interestingly enough, in the Gnostic Gospel of Judas, Judas is portrayed as receiving instructions from Jesus to betray him because it is part of a greater plan.

Any responses are welcome.