Is God generous?

I’m in Melbourne at the moment, so tonight (Sunday night) I went to my old church, where I was baptised four years ago.
We read the parable (or riddle, as I’ve been thinking of them) about the workers at the winery (Matthew 20:1-16), and then Mark (the pastor) got us to talk about whether God is generous. He got us to look through some papers, and talk about whether the things that we found made God seem generous or not.
What stood out to me was a photograph of this guy at his eightieth birthday party. I thought, Maybe that’s an example of God being generous; he’s let this guy live to see his eightieth birthday. It was in the ‘Review’ section of The Age, in a review of a book about the last fifty years of African history. I then realised that it was Robert Mugabe, the president of Zimbabwe. This made me really angry. Why should this corrupt politician get to live to see eighty years?
I realised later I was being a lot like the winery workers who worked all day. They were cranky because they’d worked all day but got paid the same as those who’d worked only a little while. I was cranky because I thought God shouldn’t be generous to Mr Mugabe. I thought I was better than Mugabe because I’m only a corrupt, European civilian, which is (supposedly) much better than being a corrupt, African politician.