I'm not sure what the controversy is. While I don't agree with Target's decision, I applaud how it took place. There was no censorship or government intervention. A number of Target customers signed a petition declaring that they would prefer that Target not sell GTAV, and Target listened.
CVS in the United States decided to stop selling cigarettes because they felt it wasn't good for their customers. I don't see how this is any different. Had the government intervened and banned GTV5 from the country, I could definitely understand the angst. However, that isn't what happened in this case. This is one retailer who decided to stop selling a product. Aussies can still get their GTAV fix from other places.
I realize we are talking about Australia and not the United States, but having a free market means that that store owners have the right to sell or not sell whichever legal goods they want. I don't believe that anyone here offered this opinion, but if any one feels that Target should have been forced to continue selling GTAV, think about if that applied in the other direction.
I own GTAV, but I still support Target if they decide that the game is too violent, and I would respect any retailer that pulled it from the shelves as long as it isn't government forced.