I've been looking more into the accusations of Bergoglio's relationship with Argentina's military dictatorship in the 70s and 80s.
A colleague who was in Argentina and knows and trusts Adolfo Pérez Esquivel takes his word that Bergoglio had no links with the dictatorship.
Besides the general accusation that he and the church in general did not oppose or even distance themselves enough from the dictatorship (see my previous post on the Pope re the church and government since Constantine) the main accusation that seems to be floating round is that the had something to do with the arrest of two Marxist priests who were dismissed. There really seems to be no real evidence of this. He insists he actually tried very hard to get them and others released.
It looks like much of this ill will comes from those who are unhappy that although Bergoglio advocated for the poor, he rejected Marxism and liberation theology because he saw it as too wrapped up in Marxism. There are many people who see things in black and white, right or wrong, pick a side. If you are not on the Marxists side, you are on the dictator's side.
It looks to me like Bergoglio chose a third way - the Gospel and that just wasn't good enough for some people. Kind of like how Jesus let down the zealots.