On the plus side, he was a major force in standing up against - and helping to bring peaceably to an end - totalitarian Communism in Europe. History will credit him for that.
Then there are the negatives. He brought to a screeching halt all liberalizing trends in the Church (and that's "liberalizing" in the old-fashion sense of extending liberty, not in the American sense of favoring bureaucratic governance). He stood four-square against women priests and birth control (including condoms that might have saved countless AIDS-ruined lives), and for mandatory clerical celibacy and stonewalling in the face of his Church's manifold pedophilia scandals.
And then there was his virulently reactionary view of gay people, exemplified most recently by his denouncing gay marriage as part of an "ideology of evil." A steady stream of proclamations issued by the Vatican's Congregation for the Doctrine of the Faith and approved by Pope John Paul II sought to deny gay people our full humanity. Gay adoption was labeled "gravely immoral" and a form of "doing violence" to children (and this, as the Church tolerated and covered up countless child rapes by its "celibate" priests). Gay sexuality itself was dismissed, repeatedly, as "intrinsically disordered."
A willful, persistent insistence on denigrating gay people, our
relationships and our sexuality served to irreparably darken John
Paul II's legacy, fostering ignorance and inequality, and scarring
the lives of many worldwide who looked to the Pope for spiritual
guidance. That this should be the legacy of a religious leader
whose mission was to bring a greater awareness of God's embracing
light and love is, to put it bluntly, sinful.