But still, sugarcoating the problems won't solve them, praising the things they got right won't correct the bugs or decrease the amount of barrels. That's what I mean by being too positive.
I understand just perfectly what you meant. Yet I disagree. That is not how people's behavior works. And praising the good stuff does not interfere with giving feedback about things that you want to change - you can do both! By discouraging positive feedback you sound like you are their boss (if their boss had a slavemaster mentality).
Further, nobody is sugarcoating anything. Praising things that they got right is important too, so they know what they did right and don't change it (or make more of it). By letting them know what they did right you redirect their attention to more pressing issues and they may feel more motivated.
